On 07/21/2014 07:33 PM, Anders Blomdell wrote:
On 2014-07-21 14:36, Soumya Koduri wrote:
On 07/21/2014 05:35 PM, Xavier Hernandez wrote:
On Monday 21 July 2014 13:53:19 Anders Blomdell wrote:
On 2014-07-21 13:49, Pranith Kumar Karampuri wrote:
On 07/21/2014 05:17 PM, Anders Blomdell wrote:
On 2014-07-21 13:36, Pranith Kumar Karampuri wrote:
On 07/21/2014 05:03 PM, Anders Blomdell wrote:
On 2014-07-19 04:43, Pranith Kumar Karampuri wrote:
On 07/18/2014 07:57 PM, Anders Blomdell wrote:
During testing of a 3*4 gluster (from master as of
yesterday), I encountered>>>>>> two major
weirdnesses: 1. A 'rm -rf <some_dir>' needed several
invocations to finish, each time
reporting a number of lines like these: rm: cannot
remove ‘a/b/c/d/e/f’: Directory not empty
2. After having successfully deleted all files from
the volume,
i have a single directory that is duplicated in
gluster-fuse,
like this: # ls -l /mnt/gluster
total 24 drwxr-xr-x 2 root root 12288 18 jul 16.17
work2/ drwxr-xr-x 2 root root 12288 18 jul 16.17
work2/
any idea on how to debug this issue?
What are the steps to recreate? We need to first find
what lead to this. Then probably which xlator leads to
this.>>>>
Would a pcap network dump + the result from 'tar -c
--xattrs /brick/a/gluster' on all the hosts before and
after the following commands are run be of>>>> any help:
# mount -t glusterfs gluster-host:/test /mnt/gluster #
mkdir /mnt/gluster/work2 ; # ls /mnt/gluster work2
work2
Are you using ext4?
Yes
Is this on latest upstream?
kernel is 3.14.9-200.fc20.x86_64, if that is latest upstream,
I don't know. gluster is from master as of end of last week
If there are known issues with ext4 i could switch to
something else, but during the last 15 years or so, I have
had very little problems with ext2/3/4, thats the reason for
choosing it.
The problem is afrv2 + dht + ext4 offsets. Soumya and Xavier
were working on it last I heard(CCed)
Should I switch to xfs or be guinea pig for testing a fixed
version?
There is a patch for this [1]. It should work for this particular
configuration, but there are some limitations in the general case,
specially for future scalability, that we tried to solve but it
seems quite difficult. Maybe Soumya has newer information about
that.
XFS should work without problems if you need it.
As long as it does not start using 64-bit offsets as well :-)
Sounds like I should go for XFS right now? Tell me if you need testers.
Sure. yes :)
XFS doesn't have this issue. It still seems to use 32-bit offset.
Thats right. This patch works fine with the current supported/limited
configuration. But we need a much more generalized approach or maybe
a design change as Xavi had suggested to make it more scalable.
Is that the patch in [1] you are referring to?
yes [1] is a possible solution for the current issue. This change is
still under review.
The problem in short -- 'ext4' uses large offsets/the bits which even
GlusterFS may need to store subvol id along with the offset. This
could be end up in few offsets being modified when given back to the
filesystem resulting in missing files etc. Avati has proposed a
solution to overcome this issue based on the assumption that "both
EXT4/XFS are tolerant in terms of the accuracy of the value presented
back in seekdir(). i.e, a seekdir(val) actually seeks to the entry
which has the "closest" true offset. For more info, please check
http://review.gluster.org/#/c/4711/.
This is AFAICT already in the version that failed, as commit
e0616e9314c8323dc59fca7cad6972f08d72b936
That's right. This change was done by Anand Avati in the dht translator
and it works as expected had AFR not come into picture. When the same
change was done in the AFR(v2) translator, it resulted in the loss of
brick-id.
[1] is a potential fix for now. Had to change the transform-logic in
these two translators.
But as Xavi had mentioned, our goal is to come up with a solution, to
make it uniform across all the translators without any loss of subvol-id
and keep the offset gaps to the minimal.
But this offset gap widens as and when more translators (which need
to store subvol-id) get added to the gluster stack which may
eventually result in the similar issue which you are facing now.
Thanks, Soumya
Xavi
[1] http://review.gluster.org/8201/
Thanks!
/Anders
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