* XFS memory recomendation? @ 2012-02-16 11:50 Assarsson, Emil 2012-02-17 2:49 ` Dave Chinner 0 siblings, 1 reply; 9+ messages in thread From: Assarsson, Emil @ 2012-02-16 11:50 UTC (permalink / raw) To: xfs@oss.sgi.com Hi, Are there any recommendations about how much memory I need based on the size of the file system and/or amount of files? For example: how much memory would be optimal for a 20TB file system with 3000000 files? I guess it depends on the usage pattern? Is there any way to make sure that the file allocation table stays in the memory? Best regards Emil Assarsson _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-16 11:50 XFS memory recomendation? Assarsson, Emil @ 2012-02-17 2:49 ` Dave Chinner 2012-02-17 13:05 ` Michael Monnerie 2012-02-18 1:58 ` Stan Hoeppner 0 siblings, 2 replies; 9+ messages in thread From: Dave Chinner @ 2012-02-17 2:49 UTC (permalink / raw) To: Assarsson, Emil; +Cc: xfs@oss.sgi.com On Thu, Feb 16, 2012 at 12:50:57PM +0100, Assarsson, Emil wrote: > Hi, > > Are there any recommendations about how much memory I need based > on the size of the file system and/or amount of files? For > example: how much memory would be optimal for a 20TB file system > with 3000000 files? /me shrugs > I guess it depends on the usage pattern? Totally. > Is there any way to make sure that the file allocation table stays in the memory? What's a "file allocation table"? XFS doesn't have one. :) XFS does have a sophisticated metadata cache and reclaim scheme that keeps frequently referenced metadata hot in cache, but you as a user have very little control over that because the cache size is effectively controlled by memory pressure. i.e. it's size is completely workload dependent..... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-17 2:49 ` Dave Chinner @ 2012-02-17 13:05 ` Michael Monnerie 2012-02-17 15:27 ` Assarsson, Emil 2012-02-18 1:58 ` Stan Hoeppner 1 sibling, 1 reply; 9+ messages in thread From: Michael Monnerie @ 2012-02-17 13:05 UTC (permalink / raw) To: xfs; +Cc: Assarsson, Emil [-- Attachment #1.1: Type: text/plain, Size: 486 bytes --] Am Freitag, 17. Februar 2012, 13:49:41 schrieb Dave Chinner: > What's a "file allocation table"? XFS doesn't have one. I guess he means the inode/dentry cache and such. BTW, what's the difference of inode and dentry caches? I'd like to understand the setting of /proc/sys/vm/vfs_cache_pressure -- mit freundlichen Grüssen, Michael Monnerie, Ing. BSc it-management Internet Services: Protéger http://proteger.at [gesprochen: Prot-e-schee] Tel: +43 660 / 415 6531 [-- Attachment #1.2: This is a digitally signed message part. --] [-- Type: application/pgp-signature, Size: 198 bytes --] [-- Attachment #2: Type: text/plain, Size: 121 bytes --] _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-17 13:05 ` Michael Monnerie @ 2012-02-17 15:27 ` Assarsson, Emil 2012-02-18 1:14 ` Eric Sandeen 0 siblings, 1 reply; 9+ messages in thread From: Assarsson, Emil @ 2012-02-17 15:27 UTC (permalink / raw) To: michael.monnerie@is.it-management.at; +Cc: xfs@oss.sgi.com Thanks for the answer Dave and Michael. As you might realize, I have no knowledge if the internal works of XFS :-P My problem is that the file system sometimes seems to be a bit laggy when listing directories and so on. I really don't know how to deal with it. I guess more memory always will help but where should I put the limit? Can it be a solution (ugly) to warm up the cache by making a complete "find" on the file system sending output to /dev/null? but then again it would probably be a stupid way to use precious memory for something that isn't used that often. -- Emil fre 2012-02-17 klockan 14:05 +0100 skrev Michael Monnerie: > Am Freitag, 17. Februar 2012, 13:49:41 schrieb Dave Chinner: > > What's a "file allocation table"? XFS doesn't have one. > > I guess he means the inode/dentry cache and such. > > BTW, what's the difference of inode and dentry caches? I'd like to > understand the setting of > /proc/sys/vm/vfs_cache_pressure > _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-17 15:27 ` Assarsson, Emil @ 2012-02-18 1:14 ` Eric Sandeen 0 siblings, 0 replies; 9+ messages in thread From: Eric Sandeen @ 2012-02-18 1:14 UTC (permalink / raw) To: Assarsson, Emil; +Cc: michael.monnerie@is.it-management.at, xfs@oss.sgi.com On 2/17/12 7:27 AM, Assarsson, Emil wrote: > Thanks for the answer Dave and Michael. > > As you might realize, I have no knowledge if the internal works of > XFS :-P > > My problem is that the file system sometimes seems to be a bit laggy > when listing directories and so on. This would have been a better starting point for your question. :) > I really don't know how to deal with > it. I guess more memory always will help but where should I put the > limit? How slow is slow? What kernel are you using, and what does your storage look like? How many files are in the directory? How much memory do you have, and what else is going on in the system at the time? I think you'll need to quantify it a bit more. -Eric > Can it be a solution (ugly) to warm up the cache by making a complete > "find" on the file system sending output to /dev/null? but then again it > would probably be a stupid way to use precious memory for something that > isn't used that often. > > -- > Emil > > > fre 2012-02-17 klockan 14:05 +0100 skrev Michael Monnerie: >> Am Freitag, 17. Februar 2012, 13:49:41 schrieb Dave Chinner: >>> What's a "file allocation table"? XFS doesn't have one. >> >> I guess he means the inode/dentry cache and such. >> >> BTW, what's the difference of inode and dentry caches? I'd like to >> understand the setting of >> /proc/sys/vm/vfs_cache_pressure >> > > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs > _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-17 2:49 ` Dave Chinner 2012-02-17 13:05 ` Michael Monnerie @ 2012-02-18 1:58 ` Stan Hoeppner 2012-02-18 2:17 ` Eric Sandeen 1 sibling, 1 reply; 9+ messages in thread From: Stan Hoeppner @ 2012-02-18 1:58 UTC (permalink / raw) To: Dave Chinner; +Cc: xfs@oss.sgi.com, Assarsson, Emil On 2/16/2012 8:49 PM, Dave Chinner wrote: > On Thu, Feb 16, 2012 at 12:50:57PM +0100, Assarsson, Emil wrote: >> Hi, >> >> Are there any recommendations about how much memory I need based >> on the size of the file system and/or amount of files? For >> example: how much memory would be optimal for a 20TB file system >> with 3000000 files? > > /me shrugs > >> I guess it depends on the usage pattern? > > Totally. Allow me to drag the OP's question under a different light... I have a 20TB XFS filesystem with 3000000 files. What is the minimum amount of system RAM I will need to run an xfs_check or xfs_repair or xfs_[tool] on this filesystem, assuming Linux has been put into a low overhead state, and said tool[s] has access to the bulk of the system memory? Is there a formula available so any XFS user can calculate this xfs_[tools] RAM requirement, given FS size X and file count Y? -- Stan _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-18 1:58 ` Stan Hoeppner @ 2012-02-18 2:17 ` Eric Sandeen 2012-02-19 13:16 ` Michael Monnerie 0 siblings, 1 reply; 9+ messages in thread From: Eric Sandeen @ 2012-02-18 2:17 UTC (permalink / raw) To: stan; +Cc: Assarsson, Emil, xfs@oss.sgi.com On 2/17/12 5:58 PM, Stan Hoeppner wrote: > On 2/16/2012 8:49 PM, Dave Chinner wrote: >> On Thu, Feb 16, 2012 at 12:50:57PM +0100, Assarsson, Emil wrote: >>> Hi, >>> >>> Are there any recommendations about how much memory I need based >>> on the size of the file system and/or amount of files? For >>> example: how much memory would be optimal for a 20TB file system >>> with 3000000 files? >> >> /me shrugs >> >>> I guess it depends on the usage pattern? >> >> Totally. > > Allow me to drag the OP's question under a different light... > > I have a 20TB XFS filesystem with 3000000 files. What is the minimum > amount of system RAM I will need to run an xfs_check or xfs_repair or > xfs_[tool] on this filesystem, assuming Linux has been put into a low > overhead state, and said tool[s] has access to the bulk of the system > memory? > > Is there a formula available so any XFS user can calculate this > xfs_[tools] RAM requirement, given FS size X and file count Y? > http://xfs.org/index.php/XFS_FAQ#Q:_Which_factors_influence_the_memory_usage_of_xfs_repair.3F -Eric _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-18 2:17 ` Eric Sandeen @ 2012-02-19 13:16 ` Michael Monnerie 2012-02-19 21:00 ` Eric Sandeen 0 siblings, 1 reply; 9+ messages in thread From: Michael Monnerie @ 2012-02-19 13:16 UTC (permalink / raw) To: xfs; +Cc: Eric Sandeen, stan, Assarsson, Emil [-- Attachment #1.1: Type: text/plain, Size: 1243 bytes --] Am Freitag, 17. Februar 2012, 18:17:46 schrieb Eric Sandeen: > http://xfs.org/index.php/XFS_FAQ#Q:_Which_factors_influence_the_memory > _usage_of_xfs_repair.3F I tried that, and it said "use 434": xfs_repair -n -vv -m 1 /dev/mapper/vg_orion-lv_orion_data Phase 1 - find and verify superblock... - max_mem = 1024, icount = 339648, imem = 1326, dblock = 805304256, dmem = 393214 Required memory for repair is greater that the maximum specified with the -m option. Please increase it to at least 434. But when I tried with # xfs_repair -n -vv -m 434 /dev/mapper/vg_orion-lv_orion_data it said the same again. It only worked with 435: # xfs_repair -n -vv -m 435 /dev/mapper/vg_orion-lv_orion_data (is that what you call an off-by-1 error?) Maybe that has been fixed already? This is # xfs_repair -V xfs_repair Version 3.1.6 BTW, this XFS is 3219644160 KB (3,2TB), used 2,9TB, has (df -i) 325364 inodes used, 293884 files in 31643 dirs. It seems mem usage primarily comes from inodes, not from the size of the filesystem. -- mit freundlichen Grüssen, Michael Monnerie, Ing. BSc it-management Internet Services: Protéger http://proteger.at [gesprochen: Prot-e-schee] Tel: +43 660 / 415 6531 [-- Attachment #1.2: This is a digitally signed message part. --] [-- Type: application/pgp-signature, Size: 198 bytes --] [-- Attachment #2: Type: text/plain, Size: 121 bytes --] _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: XFS memory recomendation? 2012-02-19 13:16 ` Michael Monnerie @ 2012-02-19 21:00 ` Eric Sandeen 0 siblings, 0 replies; 9+ messages in thread From: Eric Sandeen @ 2012-02-19 21:00 UTC (permalink / raw) To: Michael Monnerie; +Cc: Eric Sandeen, Assarsson, Emil, stan, xfs On 2/19/12 7:16 AM, Michael Monnerie wrote: > Am Freitag, 17. Februar 2012, 18:17:46 schrieb Eric Sandeen: >> http://xfs.org/index.php/XFS_FAQ#Q:_Which_factors_influence_the_memory >> _usage_of_xfs_repair.3F > > I tried that, and it said "use 434": That's megabytes, FWIW. > xfs_repair -n -vv -m 1 /dev/mapper/vg_orion-lv_orion_data > Phase 1 - find and verify superblock... > - max_mem = 1024, icount = 339648, imem = 1326, dblock = > 805304256, dmem = 393214 > Required memory for repair is greater that the maximum specified with > the -m option. Please increase it to at least 434. > > But when I tried with > # xfs_repair -n -vv -m 434 /dev/mapper/vg_orion-lv_orion_data > it said the same again. It only worked with 435: > # xfs_repair -n -vv -m 435 /dev/mapper/vg_orion-lv_orion_data > (is that what you call an off-by-1 error?) Yep, but really not too serious, I guess, still worth fixing though. It's only used to try to enforce the bare minimum - in reality you'd want more than that. > Maybe that has been fixed already? This is > # xfs_repair -V > xfs_repair Version 3.1.6 > > BTW, this XFS is 3219644160 KB (3,2TB), used 2,9TB, has (df -i) 325364 > inodes used, 293884 files in 31643 dirs. It seems mem usage primarily > comes from inodes, not from the size of the filesystem. _(" - max_mem = %lu, icount = %" PRIu64 ", imem = %" PRIu64 ", db lock = %" PRIu64 ", dmem = %" PRIu64 "\n"), max_mem, mp->m_sb.sb_icount, mp->m_sb.sb_icount >> (10 - 2), mp->m_sb.sb_dblocks, mp->m_sb.sb_dblocks >> (10 + 1)); so yes, inodes in use count for more in the approximation. -Eric _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2012-02-19 21:00 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-02-16 11:50 XFS memory recomendation? Assarsson, Emil 2012-02-17 2:49 ` Dave Chinner 2012-02-17 13:05 ` Michael Monnerie 2012-02-17 15:27 ` Assarsson, Emil 2012-02-18 1:14 ` Eric Sandeen 2012-02-18 1:58 ` Stan Hoeppner 2012-02-18 2:17 ` Eric Sandeen 2012-02-19 13:16 ` Michael Monnerie 2012-02-19 21:00 ` Eric Sandeen
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