Re: [CentOS] The state of xfs on CentOS 6?

2014-05-28 Thread Keith Keller
On 2014-05-28, m.r...@5-cent.us m.r...@5-cent.us wrote:
 We're looking at getting an HBR (that's a technical term, honkin' big
 RAID). What I'm considering is, rather than chopping it up into 14TB or
 16TB filesystems, of using xfs for really big filesystems. The question
 that's come up is: what's the state of xfs on CentOS6? I've seen a number
 of older threads seeing problems with it - has that mostly been resolved?

I have some largish (20TB) xfs filesystems on CentOS 6, and things seem
fine.  The one issue I had, quite a while ago (and maybe even in CentOS
5?), was with growing the fs, but I grew one on CentOS 6 recently with
no problems.

 How does it work if we have some *huge* files, and lots and lots of
 smaller files?

Define huge.  It seems fine for our use with multi-dozen-GB files
(possibly getting to 100GB files) and many small files, but our load is
generally not that heavy.

--keith


-- 
kkel...@wombat.san-francisco.ca.us

___
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos


Re: [CentOS] The state of xfs on CentOS 6?

2014-05-28 Thread James A. Peltier
- Original Message -
| We're looking at getting an HBR (that's a technical term, honkin' big
| RAID). What I'm considering is, rather than chopping it up into 14TB
| or
| 16TB filesystems, of using xfs for really big filesystems. The
| question
| that's come up is: what's the state of xfs on CentOS6? I've seen a
| number
| of older threads seeing problems with it - has that mostly been
| resolved?
| How does it work if we have some *huge* files, and lots and lots of
| smaller files?
| 
| mark
| 

It works well and will be the default for RHEL 7, so that should say something. 
 However, with respect to file system size.  Be prepared to have a lot of 
memory for a file system that is large and a lot of files should you ever need 
to do a file system check. ;)

-- 
James A. Peltier
Manager, IT Services - Research Computing Group
Simon Fraser University - Burnaby Campus
Phone   : 778-782-6573
Fax : 778-782-3045
E-Mail  : jpelt...@sfu.ca
Website : http://www.sfu.ca/itservices

To be original seek your inspiration from unexpected sources.
___
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos


Re: [CentOS] The state of xfs on CentOS 6?

2014-05-28 Thread John R Pierce
On 5/28/2014 11:13 AM, m.r...@5-cent.us wrote:
 We're looking at getting an HBR (that's a technical term, honkin' big
 RAID). What I'm considering is, rather than chopping it up into 14TB or
 16TB filesystems, of using xfs for really big filesystems. The question
 that's come up is: what's the state of xfs on CentOS6? I've seen a number
 of older threads seeing problems with it - has that mostly been resolved?
 How does it work if we have some*huge*  files, and lots and lots of
 smaller files?


I've had good luck with XFS file systems of 80TB or so for nearline 
archival storage.   thats 36 3TB SAS drives organized as 3 x 11 raid6+0 
with 3 hotspares.

found two minor(?) gotchas so far with XFS

1) NFS doesn't like 64bit inodes.  you can A) only nfs share the root of 
the giant XFS file system (this *is* the traditional way, but people 
from a Windows background seem to like to micromanage their shares), or 
B) use UUID exports (not compatible with all nfs clients in my 
experience), or C) specify fsid=NNN for a arbitrary unique NNN for each 
export on a given server.We opted for C.

2) I just discovered the other night that KVM doesn't like  booting disk 
image files stored on xfs on a 4K sector device (in my case, this was an 
SSD).   solution was to specify cache=writeback, which somehow bypasses 
O_DIRECT.  There's probably other fixes, but that works well enough.

also, there was a bad kernel in 6.3 or something, that had a serious bug 
with XFS.the fix came out 2-3 weeks after 6.3 was released, but I 
ran into internal operations people who don't update production systems, 
if you say you tested something on 6.3, then they use 6.3 forever.
They pathologically skip my installation step 2, yum -y update.



-- 
john r pierce  37N 122W
somewhere on the middle of the left coast

___
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos


Re: [CentOS] The state of xfs on CentOS 6?

2014-05-28 Thread James A. Peltier
- Original Message -
| On 5/28/2014 11:13 AM, m.r...@5-cent.us wrote:
|  We're looking at getting an HBR (that's a technical term, honkin'
|  big
|  RAID). What I'm considering is, rather than chopping it up into
|  14TB or
|  16TB filesystems, of using xfs for really big filesystems. The
|  question
|  that's come up is: what's the state of xfs on CentOS6? I've seen a
|  number
|  of older threads seeing problems with it - has that mostly been
|  resolved?
|  How does it work if we have some*huge*  files, and lots and lots of
|  smaller files?
| 
| 
| I've had good luck with XFS file systems of 80TB or so for nearline
| archival storage.   thats 36 3TB SAS drives organized as 3 x 11
| raid6+0
| with 3 hotspares.
| 
| found two minor(?) gotchas so far with XFS
| 
| 1) NFS doesn't like 64bit inodes.  you can A) only nfs share the root
| of
| the giant XFS file system (this *is* the traditional way, but people
| from a Windows background seem to like to micromanage their shares),
| or
| B) use UUID exports (not compatible with all nfs clients in my
| experience), or C) specify fsid=NNN for a arbitrary unique NNN for
| each
| export on a given server.We opted for C.
| 
| 2) I just discovered the other night that KVM doesn't like  booting
| disk
| image files stored on xfs on a 4K sector device (in my case, this was
| an
| SSD).   solution was to specify cache=writeback, which somehow
| bypasses
| O_DIRECT.  There's probably other fixes, but that works well enough.
| 
| also, there was a bad kernel in 6.3 or something, that had a serious
| bug
| with XFS.the fix came out 2-3 weeks after 6.3 was released, but I
| ran into internal operations people who don't update production
| systems,
| if you say you tested something on 6.3, then they use 6.3 forever.
| They pathologically skip my installation step 2, yum -y update.

Would this be the xfs_asynd chewing up CPU time bug?  If that's the one, it was 
just spinning and didn't actually cause problems except that the load went 
berserk.  In either case, there have been bugs with *every file system* I've 
used with large volumes, but XFS remains my goto file system for all large 
volumes as it is the best performance/stability match out there.

-- 
James A. Peltier
Manager, IT Services - Research Computing Group
Simon Fraser University - Burnaby Campus
Phone   : 778-782-6573
Fax : 778-782-3045
E-Mail  : jpelt...@sfu.ca
Website : http://www.sfu.ca/itservices

To be original seek your inspiration from unexpected sources.
___
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos


Re: [CentOS] The state of xfs on CentOS 6?

2014-05-28 Thread John R Pierce
On 5/28/2014 12:35 PM, James A. Peltier wrote:
 Would this be the xfs_asynd chewing up CPU time bug?  If that's the one, it 
 was just spinning and didn't actually cause problems except that the load 
 went berserk.  In either case, there have been bugs with*every file system*  
 I've used with large volumes, but XFS remains my goto file system for all 
 large volumes as it is the best performance/stability match out there.

no, this bug actually caused a big chunk of directories to disappear 
after a power failure event.  I might be wrong about 6.3, it could have 
been 6.2 or something.

I agree, XFS is my goto linux file system for large volumes. ZFS is 
my other favorite, but I still don't trust it on Linux.



-- 
john r pierce  37N 122W
somewhere on the middle of the left coast

___
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos