V5 format and man mkfs.xfs
Hi
How seriously meant is "V5 isn't experimental anymore"?
I ask because the man-page only mentions the syntax to enable it by accident. A.k.a. the backport of ftype to V4.
(man-page of xfsprogs 3.2.0 in Debian-SID)
And you still have to know that crc means V5.
Signature · 6 lines
Matthias _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs
Quoted 3 lines · Matthias Schniedermeyer
Hi
How seriously meant is "V5 isn't experimental anymore"?
"Fully supported" isn't a clear enough statement?
Quoted 3 lines
I ask because the man-page only mentions the syntax to enable it by accident. A.k.a. the backport of ftype to V4.
(man-page of xfsprogs 3.2.0 in Debian-SID)
That's intentional. V5 superblocks are an implementation detail that most users don't even need to know about. They care about the name of the features they are enabling at mkfs time, not the details of the on-disk implementation of those features.
Quoted 1 line
And you still have to know that crc means V5.
Why do you care about the format mkfs.xfs chooses for you - it's based on the features you requested. V5 isn't magically faster than V4 - there are many cases where it is slower due to CRC overhead or the overhead of the larger inode it requires. So unless you request a feature that requires it at mkfs time, you don't get that format.
In a year or so we'll change the mkfs default so that CRCs are enabled by default, but we can't do that until all the distro's have had time to pick up a kernel that fully supports the CRC feature....
Cheers,
Dave.
Signature · 7 lines
Dave Chinner [email protected] _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs
Quoted 6 lines · Dave Chinner
Quoted 3 lines · Matthias Schniedermeyer
Hi
How seriously meant is "V5 isn't experimental anymore"?
"Fully supported" isn't a clear enough statement?
I guess that was a "selective memory"-bug on my side.
Quoted 8 lines
Quoted 3 lines
I ask because the man-page only mentions the syntax to enable it by accident. A.k.a. the backport of ftype to V4.
(man-page of xfsprogs 3.2.0 in Debian-SID)That's intentional. V5 superblocks are an implementation detail that most users don't even need to know about. They care about the name of the features they are enabling at mkfs time, not the details of the on-disk implementation of those features.
The question still stands.
The crc-option is only mentioned "by accident".
Without the ftype backport there would be no mention of the "feature crc".
Furthermore i suspect that the ftype-feature also wouldn't be mentionted without the V4 backport.
Which beggs the question, what other features are "burried" in V5 that aren't mentioned in the man-page.
And are there any other "-m" options, because "-m" (asside from the ftype accident) is completly undocumented.
Quoted 4 lines
Quoted 1 line
And you still have to know that crc means V5.
Why do you care about the format mkfs.xfs chooses for you - it's based on the features you requested. V5 isn't magically faster than
I find the crc feature relativly important.
I personally had exprienced an USB enclosure(-model. As in i had several of those) that under rare circumstances flipped or cleared a single bit in a specific bit-pattern). Such corruption most likely ends up inside a data-file because most times there is more data than meta-data. But COULD happend inside the meta-data.
Since that day i have nearly everything MD5(or SHA256)ed so i can at least detect if i have a data-corruption.
Fortunatly that never happend again after i replaced that enclosure model. Which i can say with pretty high confidence.
Quoted 4 lines
V4 - there are many cases where it is slower due to CRC overhead or the overhead of the larger inode it requires. So unless you request a feature that requires it at mkfs time, you don't get that format.
Are there any feature besides crc/ftype in V5?
But i guess for "-n type=1" i would get a V4 + feature_bit.
And "-m crc=1" chooses V5 and i get ftype as a bonus (If i understand correctly).
Quoted 3 lines
In a year or so we'll change the mkfs default so that CRCs are enabled by default, but we can't do that until all the distro's have had time to pick up a kernel that fully supports the CRC feature....
OK. So V5 will be the future default.
Signature · 6 lines
Matthias _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs
Quoted 19 lines · Matthias Schniedermeyer
Quoted 6 lines · Dave Chinner
Quoted 3 lines · Matthias Schniedermeyer
Hi
How seriously meant is "V5 isn't experimental anymore"?
"Fully supported" isn't a clear enough statement?
I guess that was a "selective memory"-bug on my side.
Quoted 8 lines
Quoted 3 lines
I ask because the man-page only mentions the syntax to enable it by accident. A.k.a. the backport of ftype to V4.
(man-page of xfsprogs 3.2.0 in Debian-SID)That's intentional. V5 superblocks are an implementation detail that most users don't even need to know about. They care about the name of the features they are enabling at mkfs time, not the details of the on-disk implementation of those features.
Quoted 5 lines
The question still stands.
The crc-option is only mentioned "by accident".
Without the ftype backport there would be no mention of the "feature crc".
Ok, so you're not reporting that we don't mention V5 filesystems as "V5" filesystems. You're reporting that the "-m crc" option is not documented. That's an oversight, and needs to be fixed.
Cheers,
Dave.
Signature · 7 lines
Dave Chinner [email protected] _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs
Quoted 53 lines · Matthias Schniedermeyer
Quoted 1 line · Dave Chinner
On Tue, Jun 17, 2014 at 10:26:51AM +0200, Matthias Schniedermeyer
Quoted 5 lines · wrote:
Quoted 3 lines
Hi
How seriously meant is "V5 isn't experimental anymore"?
"Fully supported" isn't a clear enough statement?
I guess that was a "selective memory"-bug on my side.
Quoted 9 lines
Quoted 4 lines
I ask because the man-page only mentions the syntax to enable it by
accident. A.k.a. the backport of ftype to V4.
(man-page of xfsprogs 3.2.0 in Debian-SID)That's intentional. V5 superblocks are an implementation detail that most users don't even need to know about. They care about the name of the features they are enabling at mkfs time, not the details of the on-disk implementation of those features.
The question still stands.
The crc-option is only mentioned "by accident".
Without the ftype backport there would be no mention of the "feature crc".Furthermore i suspect that the ftype-feature also wouldn't be mentionted
without the V4 backport.Which beggs the question, what other features are "burried" in V5 that aren't mentioned in the man-page.
And are there any other "-m" options, because "-m" (asside from the ftype accident) is completly undocumented.
Quoted 4 lines
Quoted 1 line
And you still have to know that crc means V5.
Why do you care about the format mkfs.xfs chooses for you - it's based on the features you requested. V5 isn't magically faster than
I find the crc feature relativly important.
I personally had exprienced an USB enclosure(-model. As in i had several
of those) that under rare circumstances flipped or cleared a single bitin a specific bit-pattern). Such corruption most likely ends up inside a
data-file because most times there is more data than meta-data. But COULD happend inside the meta-data.
Quoted 5 lines
Since that day i have nearly everything MD5(or SHA256)ed so i can at least detect if i have a data-corruption.
Fortunatly that never happend again after i replaced that enclosure model. Which i can say with pretty high confidence.
I md5 hash a lot of important files. I've seen lots of failures to verify over the years. As you note, it is typically a hardware failure, but they happen none the less.
Recently the most common failure has been the sata cables. They are not very robust if you connect/disconnect them very often.
Greg
Signature · 6 lines
Sent from my Android phone with K-9 Mail. Please excuse my brevity. _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs