Use of WD20EARS with MDADM
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Note, they have 4K sectors.
Thank you for your kind responses.
Quoted 7 lines · Andrew Dunn
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Quoted 8 lines
Note, they have 4K sectors.
Thank you for your kind responses.
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Might not have ERC / TLER settable, see the other WD drive (WD360GD) here:
http://forums.storagereview.com/index.php/topic/28333-tler-cctl/
however only 1 WD drive is listed (WD360GD), no info is there specifically on WD20EARS
Good luck
Update that list if you buy it :-)
Quoted 18 lines · Asdo
Quoted 8 lines · Andrew Dunn
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Quoted 8 lines
Note, they have 4K sectors.
Thank you for your kind responses.
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Quoted 8 lines
Might not have ERC / TLER settable, see the other WD drive (WD360GD) here:
http://forums.storagereview.com/index.php/topic/28333-tler-cctl/
however only 1 WD drive is listed (WD360GD), no info is there specifically on WD20EARSGood luck
Update that list if you buy it :-)
I'm wondering where the guy in the link you provided got the command:
smartctl -l scterc d:
Assuming a Linux shift to
smartctl -l scterc /dev/sda
I get an error message:
gandalf ~ # smartctl -l scterc /dev/sda
smartctl 5.39.1 2010-01-28 r3054 [x86_64-pc-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
=======> INVALID ARGUMENT TO -l: scterc
=======> VALID ARGUMENTS ARE: error, selftest, selective, directory[,g|s], background, scttemp[sts|hist], sasphy[,reset], sataphy[,reset], gplog,N[,RANGE], smartlog,N[,RANGE], xerror[,N][,error], xselftest[,N][,selftest] <=======
Use smartctl -h to get a usage summary
gandalf ~ #
Google has a few more links of folks using that command, but less than 1 page.
I have 6 WD10EARS drives that I'm going to try out, possibly this weekend, for the first time. We'll see how it goes. I'm a newbie with RAID and LVM. My requirements are, for the most part, very modest in terms of speed and lifetime. The RAID is just for basic backup protection of other stuff.
Cheers,
Mark
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On 25/03/2010 17:58, Mark Knecht wrote:
[...]
Quoted 3 lines
I'm wondering where the guy in the link you provided got the command:
smartctl -l scterc d:
In smartmontools SVN.
Cheers,
John.
Quoted 14 lines · Mark Knecht
Quoted 9 lines · Asdo
Might not have ERC / TLER settable, see the other WD drive (WD360GD) here:
http://forums.storagereview.com/index.php/topic/28333-tler-cctl/
however only 1 WD drive is listed (WD360GD), no info is there specifically on WD20EARSGood luck
Update that list if you buy it :-)
I'm wondering where the guy in the link you provided got the command:
Quoted 8 lines
smartctl -l scterc d:
Assuming a Linux shift to
smartctl -l scterc
/dev/sdaI get an error message:
The feature will be added in version 5.40. Or get if from SVN
Quoted 7 lines · Andrew Dunn
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Quoted 7 lines
Note, they have 4K sectors.
Thank you for your kind responses.
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This is a low-cost consumer disk that is rated for a whole 2400 hours use in a year. You get what you pay for.
Quoted 18 lines · David Lethe
Quoted 7 lines · Andrew Dunn
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Quoted 8 lines
Note, they have 4K sectors.
Thank you for your kind responses.
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Quoted 2 lines
This is a low-cost consumer disk that is rated for a whole 2400 hours use in a year. You get what you pay for.
I think the "I" in RAID stands for inexpensive :-P
Jokes apart, don't you think frequent scrubbing (e.g. weekly for a raid-6 or 2/week for raid-1/10) is enough to compensate for this? I would be way more concerned with ERC / TLER if it proves to be nonsettable, but I might be wrong
Am 25.03.2010 18:45, schrieb Asdo:
Quoted 20 lines
Quoted 19 lines · David Lethe
Quoted 16 lines · Andrew Dunn
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Note, they have 4K sectors.
Thank you for your kind responses.
Signature · 4 lines
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Quoted 8 lines
Quoted 2 lines
This is a low-cost consumer disk that is rated for a whole 2400 hours use in a year. You get what you pay for.
I think the "I" in RAID stands for inexpensive :-P Jokes apart, don't you think frequent scrubbing (e.g. weekly for a raid-6 or 2/week for raid-1/10) is enough to compensate for this? I would be way more concerned with ERC / TLER if it proves to be nonsettable, but I might be wrong
Just for those who like to read: ERC is a feature stated in the ATA-specifications, that's why the "quick hack" for smartctl was so easy. But in the specs it is also noted, that the change a SCT-ERC-Command does will not survive a power cycle.
So y'all will probably need some udev-triggered daemon, which runs upon connecting a disk, checking if this disk is conforming to the ata-spec, then finding out if it's part of a raid array. If all answers yield "yes", it should call SCT-ERC with a configurable value, and probably some other "configure the drive"-commands (for tuning the idle timeout of wdXXears).
I'll have to think about that as a project again ...
All the best,
Stefan
Quoted 4 lines
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WD20EARS data
Hi @all,
I tested the WD20EARS at work today. They correctly report NO SCT ERC ability (unlike WDxxEADS from November 2009 on). Trying the commands nevertheless results in "command aborted".
So my recommendation would be: if you need a fast large array and want to use WD, keep enough redundancy and a cold spare. (Respectively because I returned 2 drives to Western Digital today, too. They had reallocated and pending sectors >100 and already dropped out of RAIDs.)
Or use Hitachi deskstar HDS722020ALA330 - these can set ERC timeouts and they cost about the same. We have sold about 10 times as many Hitachis compared to WDs, but had about the same amount of defective drives.
All the best,
Stefan
Re: WD20EARS data
Am 29.03.2010 18:59, schrieb Stefan /*St0fF*/ Hübner:
Quoted 6 lines
Hi @all,
I tested the WD20EARS at work today. They correctly report NO SCT ERC ability (unlike WDxxEADS from November 2009 on). Trying the commands nevertheless results in "command aborted".
Quoted 8 lines
So my recommendation would be: if you need a fast large array and want to use WD, keep enough redundancy and a cold spare. (Respectively because I returned 2 drives to Western Digital today, too. They had reallocated and pending sectors >100 and already dropped out of RAIDs.)
Or use Hitachi deskstar HDS722020ALA330 - these can set ERC timeouts and they cost about the same. We have sold about 10 times as many Hitachis compared to WDs, but had about the same amount of defective drives.
I'm sorry, the comparison is with the elder WD20EADS! Sorry...
Quoted 7 lines
All the best,
Stefan
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Quoted 39 lines · Stefan *St0fF* Huebner wrote:
Am 25.03.2010 18:45, schrieb Asdo:
Quoted 22 lines
Quoted 20 lines · David Lethe
Quoted 17 lines · Andrew Dunn
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Note, they have 4K sectors.
Thank you for your kind responses.
Signature · 4 lines
To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.htmlQuoted 9 lines
Quoted 3 lines
This is a low-cost consumer disk that is rated for a whole 2400 hours use in a year. You get what you pay for.
I think the "I" in RAID stands for inexpensive :-P Jokes apart, don't you think frequent scrubbing (e.g. weekly for a raid-6 or 2/week for raid-1/10) is enough to compensate for this? I would be way more concerned with ERC / TLER if it proves to be nonsettable, but I might be wrong
Just for those who like to read: ERC is a feature stated in the ATA-specifications, that's why the "quick hack" for smartctl was so easy. But in the specs it is also noted, that the change a SCT-ERC-Command does will not survive a power cycle.
Quoted 9 lines
So y'all will probably need some udev-triggered daemon, which runs upon connecting a disk, checking if this disk is conforming to the ata-spec, then finding out if it's part of a raid array. If all answers yield "yes", it should call SCT-ERC with a configurable value, and probably some other "configure the drive"-commands (for tuning the idle timeout of wdXXears).
I'll have to think about that as a project again ...
I would think it was easier to just add a small section to rc.local, unless you antucipate lots of errors during boot and after udev gets going.
Signature · 3 lines
Bill Davidsen <[email protected]> "We can't solve today's problems by using the same thinking we used in creating them." - Einstein
Quoted 8 lines · Bill Davidsen
Quoted 7 lines · Stefan *St0fF* Huebner wrote:
Am 25.03.2010 18:45, schrieb Asdo:
Quoted 5 lines
Quoted 3 lines · David Lethe
On Mar 25, 2010, at 11:20 AM, Andrew Dunn wrote:
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Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
I believe that these disks only come in the "green" variety. I recently picked up a 1.5 tb version for testing and cheap bulk storage, and I would not suggest using them in a raid array because the green drives firmware automatically parks the head after 8 seconds of inactivity and reduces the rpm of the disk. The constant parking can quickly wear out the head under high use and there is no way to disable this "feature".
Quoted 22 lines · Phillip Susi
Quoted 12 lines · Bill Davidsen
Quoted 10 lines · Stefan *St0fF* Huebner wrote:
Am 25.03.2010 18:45, schrieb Asdo:
Quoted 7 lines
Quoted 4 lines · David Lethe
On Mar 25, 2010, at 11:20 AM, Andrew Dunn wrote:
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Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Quoted 7 lines
I believe that these disks only come in the "green" variety. I recently picked up a 1.5 tb version for testing and cheap bulk storage, and I would not suggest using them in a raid array because the green drives firmware automatically parks the head after 8 seconds of inactivity and reduces the rpm of the disk. The constant parking can quickly wear out the head under high use and there is no way to disable this "feature".
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
Signature · 3 lines
Bill Davidsen <[email protected]> "We can't solve today's problems by using the same thinking we used in creating them." - Einstein
Quoted 8 lines · Bill Davidsen
Quoted 7 lines
I believe that these disks only come in the "green" variety. I recently picked up a 1.5 tb version for testing and cheap bulk storage, and I would not suggest using them in a raid array because the green drives firmware automatically parks the head after 8 seconds of inactivity and reduces the rpm of the disk. The constant parking can quickly wear out the head under high use and there is no way to disable this "feature".
Quoted 6 lines
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
I've used the 500G, and 2TB WD consumer green drives in md arrays, not many - about 10 in total. The older 500G drives (like many WD 2.5" drives) did frequent head unload/reloads under Linux due to interactions with the default timings of the Linux block layer, I believe. This can be fixed using WD's wdidle3.exe under DOS. You can monitor this using smartctl - look at the raw value for unloads, but it shouldn't be an issue with newer drives.
Both the 2TB and 500G drives seem to lock up and need resetting by Linux (this happens automatically) if you poll the SMART status e.g. you run smartd, or munin+smartctl etc. (the 2TB drives that I've had also seem to occasionally lock up under other workloads, but you might be able to live with this) - the SMART thing might be a firmware bug but WDC say "contact your Linux vendor" - they only provide support for Windows - I must get around to polling one of them for SMART under Windows XP for comparison.
If you're going to be trying to use a load of them in a RAID, then you need to be careful about vibration damping - they may not cope that well with vibration (check SMART high-fly-writes and hardware-ecc-recovered raw values if available). They are also not rated for 24/7 operation, I believe.
Tim.
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Quoted 1 line · Bill Davidsen
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
What I think people are worried about is that a drive might have X load/unload cycles in the data sheet (300k or 600k seem to be normal figures) and reaching this in 1-2 years of "normal" (according to the user who is running it 24/7) might be worrying (and understandably so).
Otoh these drives seem to be designed for desktop 8 hour per day use, so running them as a 24/7 fileserver under linux is not what they were designed for. I have no idea what will happen when the load/unload cycles goes over the data sheet number, but my guess is that it was put there for a reason.
Quoted 1 line
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
My personal experience from the WD20EADS drives is that around 40% of them failed within the first year of operation. This is not from a large population of drives though and wasn't due to load/unload cycles. I had no problem getting them replaced under warranty, but I'm running RAID6 nowadays :P
Signature · 1 line
Mikael Abrahamsson email: [email protected]
Quoted 4 lines · Mikael Abrahamsson
Quoted 1 line · Bill Davidsen
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
Quoted 8 lines
What I think people are worried about is that a drive might have X load/unload cycles in the data sheet (300k or 600k seem to be normal figures) and reaching this in 1-2 years of "normal" (according to the user who is running it 24/7) might be worrying (and understandably so).
Otoh these drives seem to be designed for desktop 8 hour per day use, so running them as a 24/7 fileserver under linux is not what they were designed for. I have no idea what will happen when the load/unload cycles goes over the data sheet number, but my guess is that it was put there for a reason.
Quoted 1 line
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
My personal experience from the WD20EADS drives is that around 40% of them failed within the first year of operation. This is not from a large population of drives though and wasn't due to load/unload cycles. I had no problem getting them replaced under warranty, but I'm running RAID6 nowadays :P
Sorry, you sound like a factory droid. *I* see no reason for early failure besides cheap mat'ls in construction. Were these assertations of short life to be true, I would campaign against the drive maker. (I think that they are just normalizing failure rate against warranty claims) Buy good stuff. I *wish* I could define the term by mfg. It seems Seagate, & WD don't hack it. The Japanese drives did, but since the $ dropped -
One thing seemingly missed is the relationship between storage density and drive temp.variations.. Hard drive mfgs are going to be in deep doodoo when the SSD folks get price/perf in the lead lane. This year, I predict. And maybe another 2 for long term reliability to be in the lead..
I believe that many [most?] RAID users are looking for results (long term archival) that are not intended in the design.We are about 2 generations away from that being a reality - I think.. For other users, I would suggest a mirror machine. with both machines being scrubbed daily, and media being dissimilar in mfg and mfg date.
I can't wait until Neil gets to (has to) play/work with the coming tech. Neat things are coming.
b-
Quoted 9 lines · Berkey B Walker
Quoted 6 lines · Mikael Abrahamsson
Quoted 1 line · Bill Davidsen
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
What I think people are worried about is that a drive might have X load/unload cycles in the data sheet (300k or 600k seem to be normal figures) and reaching this in 1-2 years of "normal" (according to the user who is running it 24/7) might be worrying (and understandably so).
Quoted 8 lines
Quoted 6 lines
Otoh these drives seem to be designed for desktop 8 hour per day use, so running them as a 24/7 fileserver under linux is not what they were designed for. I have no idea what will happen when the load/unload cycles goes over the data sheet number, but my guess is that it was put there for a reason.
Quoted 1 line
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
My personal experience from the WD20EADS drives is that around 40% of them failed within the first year of operation. This is not from a large population of drives though and wasn't due to load/unload cycles. I had no problem getting them replaced under warranty, but I'm running RAID6 nowadays :P
Sorry, you sound like a factory droid. *I* see no reason for early failure besides cheap mat'ls in construction. Were these assertations of short life to be true, I would campaign against the drive maker. (I think that they are just normalizing failure rate against warranty claims) Buy good stuff. I *wish* I could define the term by mfg. It seems Seagate, & WD don't hack it. The Japanese drives did, but since the $ dropped -
Let's see, first you put my name on something I was quoting (with attribution), delete the correct name of the person you are quoting, and then call me a "factory droid." So I have some idea of your attention to detail. Second, the short term failure rates are influenced by components delivered, assembly, and treatment in shipping. So assembly is controlled by the vendor, parts are influenced by supplier selected, and delivery treatment is usually selected by the retailer. A local clone maker found that delicate parts delivered on Wednesday had a higher infant mortality that other days. Regular driver had Wednesday off, sub thought "drop ship" was an unloading method, perhaps.
Quoted 2 lines
One thing seemingly missed is the relationship between storage density and drive temp.variations.. Hard drive mfgs are going to be in deep doodoo when the SSD folks get price/perf in the lead lane. This year, I predict. And maybe another 2 for long term reliability to be in the lead..
I think you're an optimist on cost equality, people are changing to green drives which are generally slower due to spin down or lower rpm, because the cost of power and cooling is important. It's not clear if current SSD tech will be around in five years, because there are new technologies coming which are inherently far more stable for multiple writes. The spinning platter may be ending, but the replacement is not in sight. In ten years I doubt current SSD tech will be in use, replaced by phase change, optical isomers, electron spin, or something still in a lab. And the deployment of user visible large sectors (write chunks, whatever) is not clear, if the next tech will work just as well with smaller sectors, this may become a moot point.
Quoted 2 lines
I believe that many [most?] RAID users are looking for results (long term archival) that are not intended in the design.We are about 2 generations away from that being a reality - I think.. For other users, I would suggest a mirror machine. with both machines being scrubbed daily, and media being dissimilar in mfg and mfg date.
It's not clear that date of manufacture is particularly critical, while date of deployment (in-use hours), probably is. But looking at the Google disk paper, a crate of drives from the same batch doesn't all drop dead at once, or close to it, so age in service is a factor, but not likely a critical factor.
Quoted 2 lines
I can't wait until Neil gets to (has to) play/work with the coming tech. Neat things are coming.
I would rather see some of the many things on the "someday list" get implemented. It's more fun to play with new stuff than polish off the uglies in the old, but the uglies are still there.
Signature · 3 lines
Bill Davidsen <[email protected]> "We can't solve today's problems by using the same thinking we used in creating them." - Einstein
Quoted 3 lines · Bill Davidsen
Quoted 1 line · Berkey B Walker
Snip...
Let's see, first you put my name on something I was quoting (with attribution), delete the correct name of the person you are quoting, and then call me a "factory droid." So I have some idea of your attention to detail.
..snip
Quoted 2 lines
I would rather see some of the many things on the "someday list" get implemented. It's more fun to play with new stuff than polish off the uglies in the old, but the uglies are still there.
Items snipped to reduce net bandwidth.
Sir, I have had and have a high regard for your posts. I will gladly give you a pass for having a seemingly unpleasant weekend. I have gone through MY archives in this manner and have found absolutely NO discrepancies between my copy of the posting to which I replied (which was NOT addressed to you, but was a complete quote, my "sent" post, the board's posting of that post, or..... your post to me (board copied). I should probably just take heat in general, for some of my postings back in my drinking days.
Sorry to have been a part of whatever was going on.
Best to you,
b-
All of the quotes are properly done. The post (read carefully) was addresses to Mikael Abrahamsson
Quoted 6 lines · Bill Davidsen
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
Indeed, I think you have too much faith in people doing sensible things.
Especially when their average customer isn't placing the drive in a
high use environment and they know it, and suggest against doing so.
Quoted 4 lines
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
I've not seen any anecdotal stories, but I have seen plenty of reports with real data showing a large number of head unloads from the SMART data after a relatively short period of use. Personally mine has a few hundred so far and I have not even used it for real storage yet, only testing. The specifications say it's good for 300,000 cycles, so do the math... getting 5 unloads per minute would lead to probable failure after 41 days. Granted that is about worst case, but still something to watch out for. In order to make it the entire 3 year warranty period, you need to stay under 11.4 unloads per hour. If you have very little IO activity, or VERY MUCH, then this is entirely possible, but more moderate loads in the middle have been observed to cause hundreds of unloads per hour.
Given that, and the fact that WD themselves have stated that you should not use these drives in a raid array, I'd either stay away, or watch out for this problem and try to take action to avoid and monitor it.
Quoted 34 lines · Phillip Susi
Quoted 7 lines · Bill Davidsen
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
Indeed, I think you have too much faith in people doing sensible things.
Especially when their average customer isn't placing the drive in a
high use environment and they know it, and suggest against doing so.Quoted 5 lines
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
I've not seen any anecdotal stories, but I have seen plenty of reports with real data showing a large number of head unloads from the SMART data after a relatively short period of use. Personally mine has a few hundred so far and I have not even used it for real storage yet, only testing. The specifications say it's good for 300,000 cycles, so do the math... getting 5 unloads per minute would lead to probable failure after 41 days. Granted that is about worst case, but still something to watch out for. In order to make it the entire 3 year warranty period, you need to stay under 11.4 unloads per hour. If you have very little IO activity, or VERY MUCH, then this is entirely possible, but more moderate loads in the middle have been observed to cause hundreds of unloads per hour.
Quoted 4 lines
Given that, and the fact that WD themselves have stated that you should not use these drives in a raid array, I'd either stay away, or watch out for this problem and try to take action to avoid and monitor it.
Part of this is my feeling that no one really knows if the drive fails after N loads, because even if WD could set the unload time down, the cycle takes time to happen, so I would bet that they are taking an educated guess. The other part is that there are lots of clerical tasks which would hit the drive, under Windows, single drive, 3-5 times a minute. Data entry comes to mind, customer support, print servers, etc. Granted that these are probably 7x5 hours a week, but I'm think 2/min, 7hr/day, 200day/yr... 168k/yr, and that's not the worst case.
Having run lots of drives (some TB of 73GB 15k rpm LVD320) MTTF is interesting, because the curve has spikes at the front from infant mortality, and at the end from old age, but it was damn quiet in the middle. I'd love to see the data on these, not because I'm going to run them but just to keep current, so when someone calls me and says they got a great deal on green drives, I'll know what to tell them.
Signature · 3 lines
Bill Davidsen <[email protected]> "We can't solve today's problems by using the same thinking we used in creating them." - Einstein
On Wed, Apr 21, 2010 at 8:14 AM, Phillip Susi <[email protected]> wrote:
<SNIP>
Quoted 13 lines
I've not seen any anecdotal stories, but I have seen plenty of reports with real data showing a large number of head unloads from the SMART data after a relatively short period of use. Personally mine has a few hundred so far and I have not even used it for real storage yet, only testing. The specifications say it's good for 300,000 cycles, so do the math... getting 5 unloads per minute would lead to probable failure after 41 days. Granted that is about worst case, but still something to watch out for. In order to make it the entire 3 year warranty period, you need to stay under 11.4 unloads per hour. If you have very little IO activity, or VERY MUCH, then this is entirely possible, but more moderate loads in the middle have been observed to cause hundreds of unloads per hour.
Quoted 3 lines
Given that, and the fact that WD themselves have stated that you should not use these drives in a raid array, I'd either stay away, or watch out for this problem and try to take action to avoid and monitor it.
I think I reported this earlier, but here is a WD10EARS drive in a standard Gentoo Linux desktop machine. The drive has 1661 hours powered up and 43508 load cycles. That's 26/hour and works out to about 14 months before it will be out of spec at 300K cycles.
This machine only gets a few hours of use a day but is generally powered up all the time. I don't know why Linux wakes this drive up roughly every two minutes, assuming it's Linux and not the drive itself or something on the motherboard, but it does.
I tried three of these drives in a RAID1 in another machine and they simply didn't work. Went off line over and over, with big wait times when they were working. I made no other changes expect changing to a WD 500GB RAID Edition drive and get almostno load cycle counts at all.
- Mark
gandalf ~ # smartctl -i /dev/sda
smartctl 5.39.1 2010-01-28 r3054 [x86_64-pc-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF INFORMATION SECTION ===
Device Model: WDC WD10EARS-00Y5B1 Serial Number: WD-WCAV55464493 Firmware Version: 80.00A80 User Capacity: 1,000,204,886,016 bytes Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Wed Apr 21 10:35:32 2010 PDT SMART support is: Available - device has SMART capability. SMART support is: Enabled
gandalf ~ #
gandalf ~ # smartctl -A /dev/sda
smartctl 5.39.1 2010-01-28 r3054 [x86_64-pc-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF READ SMART DATA SECTION === SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE
UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail
Always - 0
3 Spin_Up_Time 0x0027 129 128 021 Pre-fail
Always - 6525
4 Start_Stop_Count 0x0032 100 100 000 Old_age
Always - 21
5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail
Always - 0
7 Seek_Error_Rate 0x002e 200 200 000 Old_age
Always - 0
9 Power_On_Hours 0x0032 098 098 000 Old_age
Always - 1661
10 Spin_Retry_Count 0x0032 100 253 000 Old_age
Always - 0
11 Calibration_Retry_Count 0x0032 100 253 000 Old_age
Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age
Always - 20
192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age
Always - 5
193 Load_Cycle_Count 0x0032 186 186 000 Old_age
Always - 43508
194 Temperature_Celsius 0x0022 121 116 000 Old_age
Always - 26
196 Reallocated_Event_Count 0x0032 200 200 000 Old_age
Always - 0
197 Current_Pending_Sector 0x0032 200 200 000 Old_age
Always - 0
198 Offline_Uncorrectable 0x0030 200 200 000 Old_age
Offline - 0
199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age
Always - 0
200 Multi_Zone_Error_Rate 0x0008 200 200 000 Old_age
Offline - 0
gandalf ~ #
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Quoted 5 lines · Mark Knecht
This machine only gets a few hours of use a day but is generally powered up all the time. I don't know why Linux wakes this drive up roughly every two minutes, assuming it's Linux and not the drive itself or something on the motherboard, but it does.
This is documented here:
If you want to fix it, then wdidle3.exe worked for me. Search for:
wdidle3_1_00.zip
Tim.
Quoted 10 lines · Tim Small
Quoted 5 lines · Mark Knecht
This machine only gets a few hours of use a day but is generally powered up all the time. I don't know why Linux wakes this drive up roughly every two minutes, assuming it's Linux and not the drive itself or something on the motherboard, but it does.
This is documented here:
Quoted 9 lines
If you want to fix it, then wdidle3.exe worked for me. Search for:
wdidle3_1_00.zip
Tim.
Yeah, that's been reported here before, but how does someone run this Windows program on a remote machine that boots only Linux? Even if it was a DOS executable the machine has no floppy. I presume you are dual-boot with Windows? If so maybe I'll install Windows the next time I visit.
I presume I cannot run this in a VM?
It's unfortunate that this drive doesn't respond to APM commands either.
- Mark
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Greetings ...
Quoted 18 lines · Mark Knecht
Quoted 17 lines · Tim Small
Quoted 5 lines · Mark Knecht
This machine only gets a few hours of use a day but is generally powered up all the time. I don't know why Linux wakes this drive up roughly every two minutes, assuming it's Linux and not the drive itself or something on the motherboard, but it does.
This is documented here:
If you want to fix it, then wdidle3.exe worked for me. Search for:
wdidle3_1_00.zip
Quoted 8 lines
Quoted 2 lines
Tim.
Yeah, that's been reported here before, but how does someone run this Windows program on a remote machine that boots only Linux? Even if it was a DOS executable the machine has no floppy. I presume you are dual-boot with Windows? If so maybe I'll install Windows the next time I visit.
Why don't you download FreeDOS boot floppy image. Add the DOS
program to the image. Copy image to your boot partition, add an entry in your Boot Manager to boot the image using some line syslinux image booter.
On CentOS, install syslinux package using "yum install syslinux" Copy memdisk to your boot partition
From the www.freedos.org web site, download floppy image in
http://www.freedos.org/freedos/files/ ...
wget -vb http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.0/fdboot.img
Mount the downloaded image file with "mount fdboot.img /mnt/floppy/ -o rw,loop"
Copy DOS program into the floppy image.
Add to your grub.conf file ...
title FreeDOS - Boot Image
kernel memdisk
initrd fdboot.img
Now reboot your system that does not have a floppy drive off the FreeDOS image and run the DOS program to make changes. The only thing I can think of that might be a problem, is that you might have the drive attached to a SATA port that is not supported by the DOS program or something like that.
This is what I use to do BIOS and other firmware updates, that Linux does not have a tool for.
Mailed
LeeT
P.S. Sorry for the Off Topic post, but I hope it helps.
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+1 Insightful.
This is a gem of a tip - so much so that I've archived the text of this as I KNOW it will come in handy soon.
It may be been semi-off topic, but it is worth its weight in gold!
Thankyou!
Quoted 4 lines · Clinton Lee Taylor
Greetings ...
Quoted 1 line · Mark Knecht
On Wed, Apr 21, 2010 at 11:40 AM, Tim Small <[email protected]>
Quoted 11 lines · wrote:
Quoted 11 lines
Quoted 11 lines
Quoted 5 lines · Mark Knecht
This machine only gets a few hours of use a day but is generally powered up all the time. I don't know why Linux wakes this drive up roughly every two minutes, assuming it's Linux and not the drive itself or something on the motherboard, but it does.
This is documented here:
Quoted 19 lines
Quoted 6 lines
Quoted 6 lines
If you want to fix it, then wdidle3.exe worked for me. Search for:
wdidle3_1_00.zip
Quoted 8 lines
Quoted 2 lines
Tim.
Yeah, that's been reported here before, but how does someone run this Windows program on a remote machine that boots only Linux? Even if it was a DOS executable the machine has no floppy. I presume you are dual-boot with Windows? If so maybe I'll install Windows the next time I visit.
Why don't you download FreeDOS boot floppy image. Add the DOS
program to the image. Copy image to your boot partition, add an entry in your Boot Manager to boot the image using some line syslinux image booter.
Quoted 8 lines
On CentOS, install syslinux package using "yum install syslinux" Copy memdisk to your boot partition
From the www.freedos.org web site, download floppy image in
http://www.freedos.org/freedos/files/ ...wget -vb
http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.0/fdboot.img
Quoted 29 lines
Mount the downloaded image file with "mount fdboot.img
/mnt/floppy/-o rw,loop"Copy DOS program into the floppy image.
Add to your grub.conf file ...
title FreeDOS - Boot Image
kernel memdisk
initrd fdboot.imgNow reboot your system that does not have a floppy drive off the FreeDOS image and run the DOS program to make changes. The only thing I can think of that might be a problem, is that you might have the drive attached to a SATA port that is not supported by the DOS program or something like that.
This is what I use to do BIOS and other firmware updates, that Linux does not have a tool for.
Mailed
LeeT
P.S. Sorry for the Off Topic post, but I hope it helps.
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Signature · 10 lines
Steven Haigh Email: [email protected] Web: http://www.crc.id.au Phone: (03) 9001 6090 - 0412 935 897 Fax: (03) 8338 0299 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Quoted 1 line · Mark Knecht
It's unfortunate that this drive doesn't respond to APM commands either.
Yes it is.... would be nice if they made it respond to the standard APM command meant to configure this kind of behavior instead of creating a proprietary command and dos utility to invoke it. It's also a shame the drive lies about its physical sector size and has no way to turn that off. Might be a nice project to reverse engineer this utility on windows to figure out the command it sends down and add it to hdparm.
Quoted 9 lines · Phillip Susi
Quoted 1 line · Mark Knecht
It's unfortunate that this drive doesn't respond to APM commands either.
Yes it is.... would be nice if they made it respond to the standard APM command meant to configure this kind of behavior instead of creating a proprietary command and dos utility to invoke it. It's also a shame the drive lies about its physical sector size and has no way to turn that off. Might be a nice project to reverse engineer this utility on windows to figure out the command it sends down and add it to hdparm.
I thought the same thing so I worked with the hdparm developer (Mark Lord) and gave him data two months back. There was a command he had me run (hdparm --istdout /dev/sda) that extracts firmware tables or something and he spent time looking at the tables only to decide that WD simply isn't identifying anywhere in the tables that the drive is 4K/ physical sector. With that it doesn't seem that hdparm could ever do anything automatic that would be safe.
- Mark
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Quoted 11 lines · Phillip Susi
Quoted 2 lines · Mark Knecht
It's unfortunate that this drive doesn't respond to APM commands either.
Yes it is.... would be nice if they made it respond to the standard APM command meant to configure this kind of behavior instead of creating a proprietary command and dos utility to invoke it. It's also a shame the drive lies about its physical sector size and has no way to turn that off. Might be a nice project to reverse engineer this utility on windows to figure out the command it sends down and add it to hdparm.
I did have a look at this a while ago (it seemed to be built with Watcom (now open-source) and a public-domain DOS extended along with an open-sourced binary-compressor - decompilation under Watcom on FreeDOS seemed possible), and it seems that Mark Lord has done a chunk more hacking on it, since there is a reference to initial support in the latest hdparm changelog - which you might want to take a look at....
Cheers,
Tim.
wdidle3
In reply to Mark KnechtQuoted 5 lines · Mark Knecht
Quoted 1 line
[wdidle3.exe]...
Yeah, that's been reported here before, but how does someone run this Windows program on a remote machine that boots only Linux? Even if it was a DOS executable the machine has no floppy.
It is a DOS executable. As previously mentioned, you can use:
USB floppy emulation (if the BIOS supports it)
USB HD emulation
Booting from an HD partition (e.g. temporarily break RAID for one of the swap partitons, and install DOS in that partition).
syslinux + memdisk + image file
pxelinux + memdisk + image file
I use the latter for using DOS bios upgrades etc. remotely using IPMI+SoL.
If anyone want to try and reverse-engineer wdidle3, it appears to have been compiled with Watcom (now open source), and a free DOS extender and then packed (again using an open tool). You can run it under the Watcom disassembler / debugger (which is packaged with FreeDOS).
With all this open source software rattling around Western Digital, it'd be nice if they just did a bloody Linux version (or at least documented the vendor-specific commands which they use).
Tim.
Quoted 6 lines
I believe that these disks only come in the "green" variety. I recently picked up a 1.5 tb version for testing and cheap bulk storage, and I would not suggest using them in a raid array because the green drives firmware automatically parks the head after 8 seconds of inactivity and reduces the rpm of the disk. The constant parking can quickly wear out the head under high use and there is no way to disable this "feature".
As previously mentioned wdidle utility can disable the head unloading.
Quoted 8 lines
The specifications say it's good for 300,000 cycles, so do the math... getting 5 unloads per minute would lead to probable failure after 41 days. Granted that is about worst case, but still something to watch out for. In order to make it the entire 3 year warranty period, you need to stay under 11.4 unloads per hour. If you have very little IO activity, or VERY MUCH, then this is entirely possible, but more moderate loads in the middle have been observed to cause hundreds of unloads per hour.
WD mentions in the customer help (Answer ID 5357) that these newer drives were validated to 1M load/unload cycles and not 300K.
Quoted 5 lines
If you want to fix it, then wdidle3.exe worked for me. Search for:
wdidle3_1_00.zip
It worked fine for me too. I had a Load Cycle Count of 59, 15 mins after connecting the drive for the first time. After running wdidle the Count stopped at 104 and never increased again. I now have 11 hours With wdidle 1.00 disabling the timer did nothing. I had to set the timer to a large value. There is a newer version though (1.03) that supports these new drives better.
Quoted 18 lines · Khelben Blackstaff
Quoted 6 lines
I believe that these disks only come in the "green" variety. I recently picked up a 1.5 tb version for testing and cheap bulk storage, and I would not suggest using them in a raid array because the green drives firmware automatically parks the head after 8 seconds of inactivity and reduces the rpm of the disk. The constant parking can quickly wear out the head under high use and there is no way to disable this "feature".
As previously mentioned wdidle utility can disable the head unloading.
Quoted 8 lines
The specifications say it's good for 300,000 cycles, so do the math... getting 5 unloads per minute would lead to probable failure after 41 days. Granted that is about worst case, but still something to watch out for. In order to make it the entire 3 year warranty period, you need to stay under 11.4 unloads per hour. If you have very little IO activity, or VERY MUCH, then this is entirely possible, but more moderate loads in the middle have been observed to cause hundreds of unloads per hour.
Quoted 8 lines
WD mentions in the customer help (Answer ID 5357) that these newer drives were validated to 1M load/unload cycles and not 300K.
Quoted 5 lines
If you want to fix it, then wdidle3.exe worked for me. Search for:
wdidle3_1_00.zip
I just looked at a WD green drive that was in a RAID1 set for several months. The drive is an older model -- WD10EADS, but I think similar. I did not use the widdle utility and the S.M.A.R.T. data reports a load cycle count of 42. The RAID set held user directories, so it was either under constant access (daytime) or not at all (nighttime, apart from during backups).
Simon
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Quoted 2 lines · Khelben Blackstaff
WD mentions in the customer help (Answer ID 5357) that these newer drives were validated to 1M load/unload cycles and not 300K.
Weird, I wonder if they just forgot to update the spec sheet for the drive then since it says 300k.
Quoted 6 lines · Phillip Susi
Quoted 2 lines · Khelben Blackstaff
WD mentions in the customer help (Answer ID 5357) that these newer drives were validated to 1M load/unload cycles and not 300K.
Weird, I wonder if they just forgot to update the spec sheet for the drive then since it says 300k.
Validated doesn't mean spec'ed, right? So they spec it at 300K but they test and find that some units go to 1M, so they report that some units go to 1M but they keep the spec at 300K. We feel more comfortable with the operation but if the drive fails at 400K then they are within their rights to say the drive lived a useful life and replace or not replace it as they see fit.
I have 7 of these WD10EARS green drives, one in the machine I reported on that's 350 miles away, but 6 sitting in boxes here. I think I'll look into using the WD program to modify one or two of them and then start some testing.
Keep in mind that just because we possibly solve the load cycle count problem doesn't mean that the drive will work for RAID. WD has also stated that these drives don't have any TLER features.
I'll report back how that goes, but I don't know exactly when.
Cheers,
Mark
Quoted 3 lines · Mark Knecht
Keep in mind that just because we possibly solve the load cycle count problem doesn't mean that the drive will work for RAID. WD has also stated that these drives don't have any TLER features.
I completely agree and wonder if some have unrealistic expectations.
The WD20EARS is listed as a desktop drive and is cheap - $/GB.
The RE-GP, (if you need the green features, otherwise RE series), version WD2002FYPS cost more and has the following extra features over the WD20EARS:
RAFF - vibration handling
TLER - RAID optimised error handling
An MTBF spec and the comment
"Each drive is put through extended burn-in testing with thermal cycling to ensure reliable operation."
Which presumably helps weed out infant mortality cases. It is also interesting to note that while all the RE series drives have a spindle support bearing at both ends, only the 2TB desktop drive does.
In light of all the above, you get what you pay for and need to adjust expectations accordingly.
Regards,
Richard
Quoted 24 lines · Richard Scobie
Quoted 3 lines · Mark Knecht
Keep in mind that just because we possibly solve the load cycle count problem doesn't mean that the drive will work for RAID. WD has also stated that these drives don't have any TLER features.
I completely agree and wonder if some have unrealistic expectations.
The WD20EARS is listed as a desktop drive and is cheap - $/GB.
The RE-GP, (if you need the green features, otherwise RE series), version WD2002FYPS cost more and has the following extra features over the WD20EARS:
RAFF - vibration handling
TLER - RAID optimised error handling
An MTBF spec and the comment"Each drive is put through extended burn-in testing with thermal cycling to ensure reliable operation."
Which presumably helps weed out infant mortality cases. It is also interesting to note that while all the RE series drives have a spindle support bearing at both ends, only the 2TB desktop drive does.
Quoted 6 lines
In light of all the above, you get what you pay for and need to adjust expectations accordingly.
Regards,
Richard
<hehe!>
If drives always worked there wouldn't be much reason for RAID1, would there? ;-)
Cheers,
Mark
Quoted 6 lines · Richard Scobie
"Each drive is put through extended burn-in testing with thermal cycling to ensure reliable operation."
Which presumably helps weed out infant mortality cases. It is also interesting to note that while all the RE series drives have a spindle support bearing at both ends, only the 2TB desktop drive does.
Indeed. Pretty standard manufacturing process to weed out the infant mortality. Interesting to find out that they don't bother with these drives. That might explain why my first one died after ~24 hours of operation. What still pisses me off is that it died so hard my bios wouldn't even post with the thing plugged in, let alone let me read any SMART data from it.
Quoted 6 lines · Mark Knecht
Validated doesn't mean spec'ed, right? So they spec it at 300K but they test and find that some units go to 1M, so they report that some units go to 1M but they keep the spec at 300K. We feel more comfortable with the operation but if the drive fails at 400K then they are within their rights to say the drive lived a useful life and replace or not replace it as they see fit.
Specifications are based on validation; they don't have anything to do with the warranty. If one drive made it to a million, who cares? The question is will the majority of them? Just because one drive made it to a million hours before failing does not mean a million hours is the MTBF, nor does a drive failing at half MTBF have anything to do with whether it is still under warranty or not. The warranty is expressed in real time duration, not hours of operation or head unload count.
The question is, if you have a dozen drives in a raid array, is there a good chance that none will fail after they hit 300,000 unloads. If the answer to that is no, and it looks like they will reach 300,000 unloads in a few months, then you probably don't want to use those drives.
Quoted 3 lines
Keep in mind that just because we possibly solve the load cycle count problem doesn't mean that the drive will work for RAID. WD has also stated that these drives don't have any TLER features.
TLER sounds like marketing department BS to me. ANY drive should be able to retry a read plenty of times and give up in less than 7 seconds without some special feature. I've never used a drive with this "feature" and never had mdadm kick a drive offline just because it developed a bad sector. Usually I notice from a smart check and force a write to the sector and the drive remaps it.
Quoted 40 lines · Bill Davidsen
Quoted 24 lines · Phillip Susi
Quoted 13 lines · Bill Davidsen
Quoted 10 lines · Stefan *St0fF* Huebner wrote:
Am 25.03.2010 18:45, schrieb Asdo:
Quoted 7 lines
Quoted 4 lines · David Lethe
Quoted 1 line · Andrew Dunn
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Quoted 7 lines
I believe that these disks only come in the "green" variety. I recently picked up a 1.5 tb version for testing and cheap bulk storage, and I would not suggest using them in a raid array because the green drives firmware automatically parks the head after 8 seconds of inactivity and reduces the rpm of the disk. The constant parking can quickly wear out the head under high use and there is no way to disable this "feature".
I hear this said, but I don't have any data to back it up. Drive vendors aren't stupid, so if the parking feature is likely to cause premature failures under warranty, I would expect that the feature would not be there, or that the drive would be made more robust. Maybe I have too much faith in greed as a design goal, but I have to wonder if load cycles are as destructive as seems to be the assumption.
Quoted 4 lines
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
It's not hard data, but there was discussion of a similar issue fours years ago related to load/unload cycles on laptops under Ubuntu:
https://bugs.launchpad.net/ubuntu/+source/acpi-support/+bug/59695
Simon
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Quoted 4 lines · Bill Davidsen
I'd love to find some real data, anecdotal stories about older drives are not overly helpful. Clearly there is a trade-off between energy saving, response, and durability, I just don't have any data from a large population of new (green) drives.
I can add some very limited, (6 drives) observations on the 2GB RE version - WD2002FYPS.
These are green drives and have been running continuously in an md RAID5 for eight months without any problems and no drive settings have been altered. This array is idle except for a nightly rsync session for an hour or so.
Looking at the SMART data, load cycle count, is 23862 which sounds like a lot, but the current VALUE entry is 193 (and started at 200 8 months ago) and the THRESHOLD value is 0.
So, if I am interpreting this trend correctly, the THRESHOLD value will be reached in about 682,000 load cycles and about 228 months.
Regards,
Richard
Quoted 12 lines · Andrew Dunn
Recently Dell is selling their WD20EARS (2TB) for 90$
This being one of the best PPG (Price Per Gigabyte) snatches I have seen, I was considering buying 8 of them for an mdadm array.
Has anyone had experience with these drives?
Note, they have 4K sectors.
Thank you for your kind responses.
Hello,
The 4096-byte sector drives work fine with mdadm. The main problem you are going to run into with the WDC Green drives is their 8 second "idle" setting. After 8 seconds, by default, the drive parks its heads. This can lead to an amazingly high Load Cycle Count (LLC) after just a month of operation due to the fact that most disk access happens around that time causing the drive to park and unpark in repeated cycles.
To fix this, find a utility called wdidle3 (I have it, if you are unable to locate it) and set the idle timeout on the drives to 300 seconds. These drives do not support TLER, there is no ability to set it via firmware anymore - WDC removed this ability sometime last year.
-Peter
On Fri, Mar 26, 2010 at 1:27 PM, Peter Kieser <[email protected]> wrote:
<SNIP>
Quoted 9 lines
Hello,
The 4096-byte sector drives work fine with mdadm. The main problem you are going to run into with the WDC Green drives is their 8 second "idle" setting. After 8 seconds, by default, the drive parks its heads. This can lead to an amazingly high Load Cycle Count (LLC) after just a month of operation due to the fact that most disk access happens around that time causing the drive to park and unpark in repeated cycles.
Quoted 6 lines
To fix this, find a utility called wdidle3 (I have it, if you are unable to locate it) and set the idle timeout on the drives to 300 seconds. These drives do not support TLER, there is no ability to set it via firmware anymore - WDC removed this ability sometime last year.
-Peter
This seems to be a windows program? I don't see a Linux version in Gentoo portage.
I could run Windows once to set it if the settings are then maintained, or do you have a Linux solution?
- Mark
Quoted 5 lines · Mark Knecht
On Fri, Mar 26, 2010 at 1:27 PM, Peter Kieser<[email protected]> wrote:
<SNIP>Quoted 2 lines
<SNIP>
Quoted 8 lines
This seems to be a windows program? I don't see a Linux version in Gentoo portage.
I could run Windows once to set it if the settings are then maintained, or do you have a Linux solution?
- Mark
It's a proprietary DOS application written by WDC that changes the settings on the hard drives firmware. The changes are permanent. You can boot off a USB key or floppy with DOS on it to run the application.
-Peter
Quoted 15 lines · Peter Kieser
Quoted 14 lines · Mark Knecht
On Fri, Mar 26, 2010 at 1:27 PM, Peter Kieser<[email protected]> wrote:
<SNIP>Quoted 3 lines
<SNIP>
This seems to be a windows program? I don't see a Linux version in Gentoo portage.
I could run Windows once to set it if the settings are then maintained, or do you have a Linux solution?
Quoted 8 lines
Quoted 2 lines
- Mark
It's a proprietary DOS application written by WDC that changes the settings on the hard drives firmware. The changes are permanent. You can boot off a USB key or floppy with DOS on it to run the application.
-Peter
OK, so possibly FreeDOS will work?
Thanks,
Mark
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Quoted 23 lines · Mark Knecht
Quoted 22 lines · Peter Kieser
Quoted 8 lines · Mark Knecht
On Fri, Mar 26, 2010 at 1:27 PM, Peter Kieser<[email protected]> wrote:
<SNIP>Quoted 3 lines
<SNIP>
Quoted 8 lines
This seems to be a windows program? I don't see a Linux version in Gentoo portage.
I could run Windows once to set it if the settings are then maintained, or do you have a Linux solution?
- Mark
It's a proprietary DOS application written by WDC that changes the settings on the hard drives firmware. The changes are permanent. You can boot off a USB key or floppy with DOS on it to run the application.
Quoted 7 lines
Quoted 1 line
-Peter
OK, so possibly FreeDOS will work?
Thanks,
Mark
Here's some data from a WD10EARS. How do I read the LCC_COUNT?
SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE
UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail
Always - 0
3 Spin_Up_Time 0x0027 129 128 021 Pre-fail
Always - 6525
4 Start_Stop_Count 0x0032 100 100 000 Old_age
Always - 19
5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail
Always - 0
7 Seek_Error_Rate 0x002e 200 200 000 Old_age
Always - 0
9 Power_On_Hours 0x0032 099 099 000 Old_age
Always - 1053
10 Spin_Retry_Count 0x0032 100 253 000 Old_age
Always - 0
11 Calibration_Retry_Count 0x0032 100 253 000 Old_age
Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age
Always - 18
192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age
Always - 5
193 Load_Cycle_Count 0x0032 191 191 000 Old_age
Always - 27557
194 Temperature_Celsius 0x0022 121 116 000 Old_age
Always - 26
196 Reallocated_Event_Count 0x0032 200 200 000 Old_age
Always - 0
197 Current_Pending_Sector 0x0032 200 200 000 Old_age
Always - 0
198 Offline_Uncorrectable 0x0030 200 200 000 Old_age
Offline - 0
199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age
Always - 0
200 Multi_Zone_Error_Rate 0x0008 200 200 000 Old_age
Offline - 0
Is it currently at 191 with a fail level of 27557?
This drive is in a desktop machine - non-RAID - that's pretty much always turned on and is maybe 4-6 weeks old at this point.
Thanks,
Mark
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Quoted 5 lines · Mark Knecht
193
Load_Cycle_Count0x0032191 191 000Old_age
Always - 27557Is it currently at 191 with a fail level of 27557?
No, its item 193 Load_Cycle_Count (LCC) and it's at 27557.
Regards,
Richard
Quoted 6 lines · Richard Scobie
Quoted 4 lines · Mark Knecht
193
Load_Cycle_Count0x0032 191 191 000 Old_age Always - 27557
Quoted 8 lines
Quoted 1 line
Is it currently at 191 with a fail level of 27557?
No, its item 193
Load_Cycle_Count(LCC) and it's at 27557.Regards,
Richard
Thanks. I don't know if that's high or low. To me it's just a number.
Following along from Matt Garman's reply I went back and looked at when I built this machine for my dad. (How many here have 85 year old fathers who have run Linux for 7 years instead of windows? Give him a cheer!) ;-) I agree with Matt about trying to save power.
This machine is 40 days old today, at least counting since he first booted it at home. It's been up and running since then.
40 Days is 3,456,000 seconds.
3,456,000 / 27557 is 125 seconds/count increase on average. So about 2 minutes.
I wonder if I'm seeing something like Matt is seeing with the drive continually being woken up. I know most of the time it just sits idle from a user's perspective, but I've done nothing to stop daemons or anything like that. It runs screen savers, gets used every day for an hour or two, but is always powered up so that I can administer it from 350 miles away.
Interesting. I'll watch it every so often and see if it's increasing in a linear fashion, as I might guess Matt's data would suggest, or doing something different. Since I sent data a while ago it's increased to 27594. (+37) That was roughly an hour ago and my dad hasn't been logged on during this time.
- Mark
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Quoted 7 lines · Mark Knecht
I wonder if I'm seeing something like Matt is seeing with the drive continually being woken up. I know most of the time it just sits idle from a user's perspective, but I've done nothing to stop daemons or anything like that. It runs screen savers, gets used every day for an hour or two, but is always powered up so that I can administer it from 350 miles away.
I originally noticed the problem after having the drives for 4 weeks. They LCC was at around 27,000 on each drive until I changed the timeout on the drives to 300 seconds.
-Peter
Quoted 6 lines · Mark Knecht
I wonder if I'm seeing something like Matt is seeing with the drive continually being woken up. I know most of the time it just sits idle from a user's perspective, but I've done nothing to stop daemons or anything like that. It runs screen savers, gets used every day for an hour or two, but is always powered up so that I can administer it from 350 miles away.
In my case, I want to emphasize the following: my WD Green drives are strictly a data store. The system runs from a compact flash card. Though I disabled them anyway, many daemons, such as syslog, sshd, cron, fetchmail, etc, should only affect the *system* drive.
However, daemons like nfs and smbd can obviously affect the data store. Even so, I wouldn't expect them to cause a disk access unless a request is made.
The point is, in my opinion, a non-system partition should be that much easier to make "truly" idle... still, I can't figure out how to do it.
-Matt
Quoted 6 lines · Matt Garman
The point is, in my opinion, a non-system partition should be that much easier to make "truly" idle... still, I can't figure out how to do it.
-Matt
I must also note, that I was seeing the drives stop and start even when there *was* activity on the disks.
-Peter
Quoted 15 lines · Mark Knecht
Quoted 1 line · Richard Scobie
No, its item 193
Load_Cycle_Count(LCC) and it's at 27557.Thanks. I don't know if that's high or low. To me it's just a number.
Following along from Matt Garman's reply I went back and looked at when I built this machine for my dad. (How many here have 85 year old fathers who have run Linux for 7 years instead of windows? Give him a cheer!) ;-) I agree with Matt about trying to save power.
This machine is 40 days old today, at least counting since he first booted it at home. It's been up and running since then.
40 Days is 3,456,000 seconds.
Quoted 8 lines
3,456,000 / 27557 is 125 seconds/count increase on average. So about 2 minutes.
I wonder if I'm seeing something like Matt is seeing with the drive continually being woken up. I know most of the time it just sits idle from a user's perspective, but I've done nothing to stop daemons or anything like that. It runs screen savers, gets used every day for an hour or two, but is always powered up so that I can administer it from 350 miles away.
Why leave the thing on 24 hours a day if it's only used 1-2 of them? Save wear on your drive and the rest of the machine, save your dad a few bucks on his electricity bill and shut the thing down when it's not used. Then use WoL to wake it up if you need to admin it, or heck, just use the BIOS/ACPI wakeup feature and put the thing to sleep at night and wake up automatically in the morning - at least then you'll cut it's run-time in half.
-Dave
Quoted 33 lines · David Rees
Quoted 15 lines · Mark Knecht
Quoted 1 line · Richard Scobie
No, its item 193
Load_Cycle_Count(LCC) and it's at 27557.Thanks. I don't know if that's high or low. To me it's just a number.
Following along from Matt Garman's reply I went back and looked at when I built this machine for my dad. (How many here have 85 year old fathers who have run Linux for 7 years instead of windows? Give him a cheer!) ;-) I agree with Matt about trying to save power.
This machine is 40 days old today, at least counting since he first booted it at home. It's been up and running since then.
40 Days is 3,456,000 seconds.
Quoted 8 lines
3,456,000 / 27557 is 125 seconds/count increase on average. So about 2 minutes.
I wonder if I'm seeing something like Matt is seeing with the drive continually being woken up. I know most of the time it just sits idle from a user's perspective, but I've done nothing to stop daemons or anything like that. It runs screen savers, gets used every day for an hour or two, but is always powered up so that I can administer it from 350 miles away.
Why leave the thing on 24 hours a day if it's only used 1-2 of them? Save wear on your drive and the rest of the machine, save your dad a few bucks on his electricity bill and shut the thing down when it's not used. Then use WoL to wake it up if you need to admin it, or heck, just use the BIOS/ACPI wakeup feature and put the thing to sleep at night and wake up automatically in the morning - at least then you'll cut it's run-time in half.
Quoted 2 lines
-Dave
That's really up to him. He doesn't hear well and doesn't seem to care about his utility bill so it's easy for me, or has been in the past. His last machine ran 5 1/2 years powered up all the time. I think the alternate view is that keeping the drive at a relatively constant temperature is a good thing also. Who knows?
As for WoL I don't know much about it but his machine is main target logging in through his router and script kiddies are for every trying to log in with name after name after name. If it could be make to respond to my IP only that would be great but my IP moves around now and then so how do I make that work?
(NOT a topic for this list...)
Cheers,
Mark
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Quoted 7 lines · Peter Kieser
The 4096-byte sector drives work fine with mdadm. The main problem you are going to run into with the WDC Green drives is their 8 second "idle" setting. After 8 seconds, by default, the drive parks its heads. This can lead to an amazingly high Load Cycle Count (LLC) after just a month of operation due to the fact that most disk access happens around that time causing the drive to park and unpark in repeated cycles.
For what it's worth... that head parking feature actually saves a measurable amount of power. On my system, with four drives, there is about a 10 watt (AC) difference between all four heads parked and all four heads non-parked. This finding is consistent with the power numbers suggested by SilentPCReview's reviews of these drives.
Quoted 5 lines
To fix this, find a utility called wdidle3 (I have it, if you are unable to locate it) and set the idle timeout on the drives to 300 seconds. These drives do not support TLER, there is no ability to set it via firmware anymore - WDC removed this ability sometime last year.
This will prevent the rapidly increasing Load Cycle Count SMART counter. However, in my opinion, it also removes a useful power-saving feature of these drives. In other words, my system is mostly idle; I want the heads to be parked the majority of the time. Instead, without the wdidle3 hack, they constantly park/unpark despite an otherwise idle system.
Here's the problem I've been unable to solve: if my system is truly idle for, say 10 minutes, then why don't my heads stay parked for 10 minutes? It appears that the heads will park, then five minutes later, *something mysterious* will cause them to unpark.
I did some experimenting with this several months ago. See the list archives for August 20, 2009, subject "linux disk access when idle"[1].
As far as I can tell, I disabled every single daemon on my system, but still could not get the heads to park for more than five minutes.
My point in all this is: I'd rather tune my software (Linux) to work better with my hardware, rather than remove what I consider to be a useful power-saving feature. I haven't re-visisted this in a while, but last time I tried, I couldn't find the guilty daemon or kernel setting responsible for the constant head un-parking.
[1] http://marc.info/?l=linux-raid&m=125078611926294&w=2
-Matt