Bad fibre channel performance: need howto
Hello,
I asked a similar question last week.
I discovered that my hard disk which can do 60mb/sec sequential read, under linux/lsilogic40909 fibre hba gives only 30mb/sec, 45 if I tweak a lot readahead (why I need to?).
I have searched a lot in internet and it seems that:
1) fibrechannel howto was in sistina home page but now disappeared
2) fibrechannel specific mailing list for linux disappeared (archives to)
Where can I search for help?
Here it not seems appropriate to me.
I have to find my bottleneck, please help with sending me docs.
Signature · 1 line
Mario Giammarco
Mario
I am/was the author of the FibreChannel HowTo.
That howto slowly got outdated (Interesting how that happens when one does not have the same amount of spare time anymore...) and we eventually decided to take it off the Sistina website.
Not sure if the howto would have helped you in diagnosing this problem anyway ;)
Erling
Quoted 24 lines · Mario Giammarco
Hello,
I asked a similar question last week.
I discovered that my hard disk which can do 60mb/sec sequential read, under linux/lsilogic40909 fibre hba gives only 30mb/sec, 45 if I tweak a lot readahead (why I need to?).I have searched a lot in internet and it seems that:
1) fibrechannel howto was in sistina home page but now disappeared
2) fibrechannel specific mailing list for linux disappeared (archives to)Where can I search for help?
Here it not seems appropriate to me.I have to find my bottleneck, please help with sending me docs.
Signature · 6 lines
Mario Giammarco - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Signature · 4 lines
Erling Nygaard ([email protected]) Key fingerprint: CA00 CF4E 9438 E348 E503 7ECF 9D94 D993 982A BDE0
Quoted 8 lines · Mario Giammarco
Hello,
I asked a similar question last week.
I discovered that my hard disk which can do 60mb/sec sequential read, under linux/lsilogic40909 fibre hba gives only 30mb/sec, 45 if I tweak a lot readahead (why I need to?).I have searched a lot in internet and it seems that:
Quoted 8 lines
1) fibrechannel howto was in sistina home page but now disappeared
2) fibrechannel specific mailing list for linux disappeared (archives to)Where can I search for help? Here it not seems appropriate to me.
I have to find my bottleneck, please help with sending me docs.
Hello Mario,
If you want, I can send you an archive of the howto.
I've downloaded it a long time ago, before sistina removed it from their server.
But, it's true, it's a bit old. Therefore, there are some basic informations about protocol that could have some interest.
About your problem, I am not sure it's really because of FibreChannel. There are a lot of differences between theorical values and real ones. Which tool are you using for the benchmark ?
Signature · 6 lines
Fabien SALVI - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Il lun, 2003-11-24 alle 11:55, Fabien Salvi ha scritto:
Quoted 9 lines
Hello Mario,
If you want, I can send you an archive of the howto.
I've downloaded it a long time ago, before sistina removed it from their server.But, it's true, it's a bit old
Yes send it to me please. I like to read all.
Quoted 3 lines
About your problem, I am not sure it's really because of FibreChannel. There are a lot of differences between theorical values and real ones. Which tool are you using for the benchmark ?
I know but usually the "sequential read" is the easiest test to discover if there are problems.
I have used hdparm and sg3 tools to do a quick sequential read test. On ide world if hdparm tells me that I have sequential transfer rate lower than shown on web reviews it means that I have to tweak dma, etc. and usually after tweaking I get performance promised.
Here there is little to tweak and I then discovered with a serious test (tiobench) that write performance is also worse.
I suppose there is some problem.
I am now buying a qlogic2200 to try if it is better. Can someone tell me best drivers for qlogic2200?
Thanks again!
Signature · 1 line
Mario Giammarco
Quoted 8 lines · Mario Giammarco
Il lun, 2003-11-24 alle 11:55, Fabien Salvi ha scritto:
Quoted 2 lines
Hello Mario,
Quoted 7 lines
Quoted 4 lines
If you want, I can send you an archive of the howto.
I've downloaded it a long time ago, before sistina removed it from their server.But, it's true, it's a bit old
Yes send it to me please. I like to read all.
Here :
ftp://ftp.cri74.org/incoming/services/3c6caf61efc733e03526edac45852ad1/fibrechannel_howto.tar.bz2
Quoted 13 lines
Quoted 3 lines
About your problem, I am not sure it's really because of FibreChannel. There are a lot of differences between theorical values and real ones. Which tool are you using for the benchmark ?
I know but usually the "sequential read" is the easiest test to discover if there are problems.
I have used hdparm and sg3 tools to do a quick sequential read test. On ide world if hdparm tells me that I have sequential transfer rate lower than shown on web reviews it means that I have to tweak dma, etc. and usually after tweaking I get performance promised.
Quoted 7 lines
Here there is little to tweak and I then discovered with a serious test (tiobench) that write performance is also worse.
I suppose there is some problem.
I am now buying a qlogic2200 to try if it is better. Can someone tell me best drivers for qlogic2200?
I use qlogic 2200 FC HBA with the official qlogic driver and it works fine. Look at: http://www.qlogic.com/support/os_detail.asp?productid=113&osid=26
Signature · 8 lines
Fabien SALVI Centre de Ressources Informatiques
Archamps, France -- http://www.cri74.org
PingOO GNU/linux distribution : http://www.pingoo.org
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