[Gluster-users] Sharding problem - multiple shard copies with mismatching gfids

Ian Halliday ihalliday at ndevix.com
Tue Apr 3 02:22:20 UTC 2018 

Raghavendra,

Sorry for the late follow up. I have some more data on the issue.

The issue tends to happen when the shards are created. The easiest time 
to reproduce this is during an initial VM disk format. This is a log 
from a test VM that was launched, and then partitioned and formatted 
with LVM / XFS:

[2018-04-03 02:05:00.838440] W [MSGID: 109048] 
[dht-common.c:9732:dht_rmdir_cached_lookup_cbk] 0-ovirt-350-zone1-dht: 
/489c6fb7-fe61-4407-8160-35c0aac40c85/images/_remove_me_9a0660e1-bd86-47ea-8e09-865c14f11f26/e2645bd1-a7f3-4cbd-9036-3d3cbc7204cd.meta 
found on cached subvol ovirt-350-zone1-replicate-5
[2018-04-03 02:07:57.967489] I [MSGID: 109070] 
[dht-common.c:2796:dht_lookup_linkfile_cbk] 0-ovirt-350-zone1-dht: 
Lookup of /.shard/927c6620-848b-4064-8c88-68a332b645c2.7 on 
ovirt-350-zone1-replicate-3 (following linkfile) failed ,gfid = 
00000000-0000-0000-0000-000000000000 [No such file or directory]
[2018-04-03 02:07:57.974815] I [MSGID: 109069] 
[dht-common.c:2095:dht_lookup_unlink_stale_linkto_cbk] 
0-ovirt-350-zone1-dht: Returned with op_ret 0 and op_errno 0 for 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3
[2018-04-03 02:07:57.979851] W [MSGID: 109009] 
[dht-common.c:2831:dht_lookup_linkfile_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3: gfid different on data 
file on ovirt-350-zone1-replicate-3, gfid local = 
00000000-0000-0000-0000-000000000000, gfid node = 
55f86aa0-e7a0-4075-b46b-a11f8bdbbceb
[2018-04-03 02:07:57.980716] W [MSGID: 109009] 
[dht-common.c:2570:dht_lookup_everywhere_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3: gfid differs on 
subvolume ovirt-350-zone1-replicate-3, gfid local = 
b1e3f299-32ff-497e-918b-090e957090f6, gfid node = 
55f86aa0-e7a0-4075-b46b-a11f8bdbbceb
[2018-04-03 02:07:57.980763] E [MSGID: 133010] 
[shard.c:1724:shard_common_lookup_shards_cbk] 0-ovirt-350-zone1-shard: 
Lookup on shard 3 failed. Base file gfid = 
927c6620-848b-4064-8c88-68a332b645c2 [Stale file handle]
[2018-04-03 02:07:57.983016] I [MSGID: 109069] 
[dht-common.c:2095:dht_lookup_unlink_stale_linkto_cbk] 
0-ovirt-350-zone1-dht: Returned with op_ret 0 and op_errno 0 for 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.7
[2018-04-03 02:07:57.988761] W [MSGID: 109009] 
[dht-common.c:2570:dht_lookup_everywhere_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3: gfid differs on 
subvolume ovirt-350-zone1-replicate-3, gfid local = 
b1e3f299-32ff-497e-918b-090e957090f6, gfid node = 
55f86aa0-e7a0-4075-b46b-a11f8bdbbceb
[2018-04-03 02:07:57.988844] W [MSGID: 109009] 
[dht-common.c:2831:dht_lookup_linkfile_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.7: gfid different on data 
file on ovirt-350-zone1-replicate-3, gfid local = 
00000000-0000-0000-0000-000000000000, gfid node = 
955a5e78-ab4c-499a-89f8-511e041167fb
[2018-04-03 02:07:57.989748] W [MSGID: 109009] 
[dht-common.c:2570:dht_lookup_everywhere_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.7: gfid differs on 
subvolume ovirt-350-zone1-replicate-3, gfid local = 
efbb9be5-0744-4883-8f3e-e8f7ce8d7741, gfid node = 
955a5e78-ab4c-499a-89f8-511e041167fb
[2018-04-03 02:07:57.989827] I [MSGID: 109069] 
[dht-common.c:2095:dht_lookup_unlink_stale_linkto_cbk] 
0-ovirt-350-zone1-dht: Returned with op_ret -1 and op_errno 2 for 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3
[2018-04-03 02:07:57.989832] E [MSGID: 133010] 
[shard.c:1724:shard_common_lookup_shards_cbk] 0-ovirt-350-zone1-shard: 
Lookup on shard 7 failed. Base file gfid = 
927c6620-848b-4064-8c88-68a332b645c2 [Stale file handle]
The message "W [MSGID: 109009] 
[dht-common.c:2831:dht_lookup_linkfile_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3: gfid different on data 
file on ovirt-350-zone1-replicate-3, gfid local = 
00000000-0000-0000-0000-000000000000, gfid node = 
55f86aa0-e7a0-4075-b46b-a11f8bdbbceb " repeated 2 times between 
[2018-04-03 02:07:57.979851] and [2018-04-03 02:07:57.995739]
[2018-04-03 02:07:57.996644] W [MSGID: 109009] 
[dht-common.c:2570:dht_lookup_everywhere_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3: gfid differs on 
subvolume ovirt-350-zone1-replicate-3, gfid local = 
0a701104-e9a2-44c0-8181-4a9a6edecf9f, gfid node = 
55f86aa0-e7a0-4075-b46b-a11f8bdbbceb
[2018-04-03 02:07:57.996761] E [MSGID: 133010] 
[shard.c:1724:shard_common_lookup_shards_cbk] 0-ovirt-350-zone1-shard: 
Lookup on shard 3 failed. Base file gfid = 
927c6620-848b-4064-8c88-68a332b645c2 [Stale file handle]
[2018-04-03 02:07:57.998986] W [MSGID: 109009] 
[dht-common.c:2831:dht_lookup_linkfile_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3: gfid different on data 
file on ovirt-350-zone1-replicate-3, gfid local = 
00000000-0000-0000-0000-000000000000, gfid node = 
55f86aa0-e7a0-4075-b46b-a11f8bdbbceb
[2018-04-03 02:07:57.999857] W [MSGID: 109009] 
[dht-common.c:2570:dht_lookup_everywhere_cbk] 0-ovirt-350-zone1-dht: 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3: gfid differs on 
subvolume ovirt-350-zone1-replicate-3, gfid local = 
0a701104-e9a2-44c0-8181-4a9a6edecf9f, gfid node = 
55f86aa0-e7a0-4075-b46b-a11f8bdbbceb
[2018-04-03 02:07:57.999899] E [MSGID: 133010] 
[shard.c:1724:shard_common_lookup_shards_cbk] 0-ovirt-350-zone1-shard: 
Lookup on shard 3 failed. Base file gfid = 
927c6620-848b-4064-8c88-68a332b645c2 [Stale file handle]
[2018-04-03 02:07:57.999942] W [fuse-bridge.c:896:fuse_attr_cbk] 
0-glusterfs-fuse: 22338: FSTAT() 
/489c6fb7-fe61-4407-8160-35c0aac40c85/images/a717e25c-f108-4367-9d28-9235bd432bb7/5a8e541e-8883-4dec-8afd-aa29f38ef502 
=> -1 (Stale file handle)
[2018-04-03 02:07:57.987941] I [MSGID: 109069] 
[dht-common.c:2095:dht_lookup_unlink_stale_linkto_cbk] 
0-ovirt-350-zone1-dht: Returned with op_ret 0 and op_errno 0 for 
/.shard/927c6620-848b-4064-8c88-68a332b645c2.3


Duplicate shards are created. Output from one of the gluster nodes:

# find -name 927c6620-848b-4064-8c88-68a332b645c2.*
./brick1/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.19
./brick1/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.9
./brick1/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.7
./brick3/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.5
./brick3/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.3
./brick4/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.19
./brick4/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.9
./brick4/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.5
./brick4/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.3
./brick4/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.7

[root at n1 gluster]# getfattr -d -m . -e hex 
./brick1/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.19
# file: brick1/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.19
security.selinux=0x73797374656d5f753a6f626a6563745f723a756e6c6162656c65645f743a733000
trusted.gfid=0x46083184a0e5468e89e6cc1db0bfc63b
trusted.gfid2path.77528eefc6a11c45=0x62653331383633382d653861302d346336642d393737642d3761393337616138343830362f39323763363632302d383438622d343036342d386338382d3638613333326236343563322e3139
trusted.glusterfs.dht.linkto=0x6f766972742d3335302d7a6f6e65312d7265706c69636174652d3300

[root at n1 gluster]# getfattr -d -m . -e hex 
./brick4/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.19
# file: brick4/brick/.shard/927c6620-848b-4064-8c88-68a332b645c2.19
security.selinux=0x73797374656d5f753a6f626a6563745f723a756e6c6162656c65645f743a733000
trusted.afr.dirty=0x000000000000000000000000
trusted.gfid=0x46083184a0e5468e89e6cc1db0bfc63b
trusted.gfid2path.77528eefc6a11c45=0x62653331383633382d653861302d346336642d393737642d3761393337616138343830362f39323763363632302d383438622d343036342d386338382d3638613333326236343563322e3139


In the above example, the shard on Brick 1 is the bad one.

At this point, the VM will pause with an unknown storage error and will 
not boot until the offending shards are removed.


# gluster volume info
Volume Name: ovirt-350-zone1
Type: Distributed-Replicate
Volume ID: 106738ed-9951-4270-822e-63c9bcd0a20e
Status: Started
Snapshot Count: 0
Number of Bricks: 7 x (2 + 1) = 21
Transport-type: tcp
Bricks:
Brick1: 10.0.6.100:/gluster/brick1/brick
Brick2: 10.0.6.101:/gluster/brick1/brick
Brick3: 10.0.6.102:/gluster/arbrick1/brick (arbiter)
Brick4: 10.0.6.100:/gluster/brick2/brick
Brick5: 10.0.6.101:/gluster/brick2/brick
Brick6: 10.0.6.102:/gluster/arbrick2/brick (arbiter)
Brick7: 10.0.6.100:/gluster/brick3/brick
Brick8: 10.0.6.101:/gluster/brick3/brick
Brick9: 10.0.6.102:/gluster/arbrick3/brick (arbiter)
Brick10: 10.0.6.100:/gluster/brick4/brick
Brick11: 10.0.6.101:/gluster/brick4/brick
Brick12: 10.0.6.102:/gluster/arbrick4/brick (arbiter)
Brick13: 10.0.6.100:/gluster/brick5/brick
Brick14: 10.0.6.101:/gluster/brick5/brick
Brick15: 10.0.6.102:/gluster/arbrick5/brick (arbiter)
Brick16: 10.0.6.100:/gluster/brick6/brick
Brick17: 10.0.6.101:/gluster/brick6/brick
Brick18: 10.0.6.102:/gluster/arbrick6/brick (arbiter)
Brick19: 10.0.6.100:/gluster/brick7/brick
Brick20: 10.0.6.101:/gluster/brick7/brick
Brick21: 10.0.6.102:/gluster/arbrick7/brick (arbiter)
Options Reconfigured:
cluster.server-quorum-type: server
cluster.data-self-heal-algorithm: full
performance.client-io-threads: off
server.allow-insecure: on
client.event-threads: 8
storage.owner-gid: 36
storage.owner-uid: 36
server.event-threads: 16
features.shard-block-size: 5GB
features.shard: on
transport.address-family: inet
nfs.disable: yes

Any suggestions?


-- Ian


------ Original Message ------
From: "Raghavendra Gowdappa" <rgowdapp at redhat.com>
To: "Krutika Dhananjay" <kdhananj at redhat.com>
Cc: "Ian Halliday" <ihalliday at ndevix.com>; "gluster-user" 
<gluster-users at gluster.org>; "Nithya Balachandran" <nbalacha at redhat.com>
Sent: 3/26/2018 2:37:21 AM
Subject: Re: [Gluster-users] Sharding problem - multiple shard copies 
with mismatching gfids

>Ian,
>
>Do you've a reproducer for this bug? If not a specific one, a general 
>outline of what operations where done on the file will help.
>
>regards,
>Raghavendra
>
>On Mon, Mar 26, 2018 at 12:55 PM, Raghavendra Gowdappa 
><rgowdapp at redhat.com> wrote:
>>
>>
>>On Mon, Mar 26, 2018 at 12:40 PM, Krutika Dhananjay 
>><kdhananj at redhat.com> wrote:
>>>The gfid mismatch here is between the shard and its "link-to" file, 
>>>the creation of which happens at a layer below that of shard 
>>>translator on the stack.
>>>
>>>Adding DHT devs to take a look.
>>
>>Thanks Krutika. I assume shard doesn't do any dentry operations like 
>>rename, link, unlink on the path of file (not the gfid handle based 
>>path) internally while managing shards. Can you confirm? If it does 
>>these operations, what fops does it do?
>>
>>@Ian,
>>
>>I can suggest following way to fix the problem:
>>* Since one of files listed is a DHT linkto file, I am assuming there 
>>is only one shard of the file. If not, please list out gfids of other 
>>shards and don't proceed with healing procedure.
>>* If gfids of all shards happen to be same and only linkto has a 
>>different gfid, please proceed to step 3. Otherwise abort the healing 
>>procedure.
>>* If cluster.lookup-optimize is set to true abort the healing 
>>procedure
>>* Delete the linkto file - the file with permissions -------T and 
>>xattr trusted.dht.linkto and do a lookup on the file from mount point 
>>after turning off readdriplus [1].
>>
>>As to reasons on how we ended up in this situation, Can you explain me 
>>what is the I/O pattern on this file - like are there lots of entry 
>>operations like rename, link, unlink etc on the file? There have been 
>>known races in rename/lookup-heal-creating-linkto where linkto and 
>>data file have different gfids. [2] fixes some of these cases
>>
>>[1] 
>>http://lists.gluster.org/pipermail/gluster-users/2017-March/030148.html 
>><http://lists.gluster.org/pipermail/gluster-users/2017-March/030148.html>
>>[2] https://review.gluster.org/#/c/19547/ 
>><https://review.gluster.org/#/c/19547/>
>>
>>regards,
>>Raghavendra
>>>
>>>>
>>>-Krutika
>>>
>>>On Mon, Mar 26, 2018 at 1:09 AM, Ian Halliday <ihalliday at ndevix.com> 
>>>wrote:
>>>>Hello all,
>>>>
>>>>We are having a rather interesting problem with one of our VM 
>>>>storage systems. The GlusterFS client is throwing errors relating to 
>>>>GFID mismatches. We traced this down to multiple shards being 
>>>>present on the gluster nodes, with different gfids.
>>>>
>>>>Hypervisor gluster mount log:
>>>>
>>>>[2018-03-25 18:54:19.261733] E [MSGID: 133010] 
>>>>[shard.c:1724:shard_common_lookup_shards_cbk] 0-ovirt-zone1-shard: 
>>>>Lookup on shard 7 failed. Base file gfid = 
>>>>87137cac-49eb-492a-8f33-8e33470d8cb7 [Stale file handle]
>>>>The message "W [MSGID: 109009] 
>>>>[dht-common.c:2162:dht_lookup_linkfile_cbk] 0-ovirt-zone1-dht: 
>>>>/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7: gfid different on 
>>>>data file on ovirt-zone1-replicate-3, gfid local = 
>>>>00000000-0000-0000-0000-000000000000, gfid node = 
>>>>57c6fcdf-52bb-4f7a-aea4-02f0dc81ff56 " repeated 2 times between 
>>>>[2018-03-25 18:54:19.253748] and [2018-03-25 18:54:19.263576]
>>>>[2018-03-25 18:54:19.264349] W [MSGID: 109009] 
>>>>[dht-common.c:1901:dht_lookup_everywhere_cbk] 0-ovirt-zone1-dht: 
>>>>/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7: gfid differs on 
>>>>subvolume ovirt-zone1-replicate-3, gfid local = 
>>>>fdf0813b-718a-4616-a51b-6999ebba9ec3, gfid node = 
>>>>57c6fcdf-52bb-4f7a-aea4-02f0dc81ff56
>>>>
>>>>
>>>>On the storage nodes, we found this:
>>>>
>>>>[root at n1 gluster]# find -name 87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>./brick2/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>./brick4/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>
>>>>[root at n1 gluster]# ls -lh 
>>>>./brick2/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>---------T. 2 root root 0 Mar 25 13:55 
>>>>./brick2/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>[root at n1 gluster]# ls -lh 
>>>>./brick4/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>-rw-rw----. 2 root root 3.8G Mar 25 13:55 
>>>>./brick4/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>
>>>>[root at n1 gluster]# getfattr -d -m . -e hex 
>>>>./brick2/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>># file: brick2/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>security.selinux=0x73797374656d5f753a6f626a6563745f723a756e6c6162656c65645f743a733000
>>>>trusted.gfid=0xfdf0813b718a4616a51b6999ebba9ec3
>>>>trusted.glusterfs.dht.linkto=0x6f766972742d3335302d7a6f6e65312d7265706c69636174652d3300
>>>>
>>>>[root at n1 gluster]# getfattr -d -m . -e hex 
>>>>./brick4/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>># file: brick4/brick/.shard/87137cac-49eb-492a-8f33-8e33470d8cb7.7
>>>>security.selinux=0x73797374656d5f753a6f626a6563745f723a756e6c6162656c65645f743a733000
>>>>trusted.afr.dirty=0x000000000000000000000000
>>>>trusted.bit-rot.version=0x020000000000000059914190000ce672
>>>>trusted.gfid=0x57c6fcdf52bb4f7aaea402f0dc81ff56
>>>>
>>>>
>>>>I'm wondering how they got created in the first place, and if anyone 
>>>>has any insight on how to fix it?
>>>>
>>>>Storage nodes:
>>>>[root at n1 gluster]# gluster --version
>>>>glusterfs 4.0.0
>>>>
>>>>[root at n1 gluster]# gluster volume info
>>>>
>>>>Volume Name: ovirt-350-zone1
>>>>Type: Distributed-Replicate
>>>>Volume ID: 106738ed-9951-4270-822e-63c9bcd0a20e
>>>>Status: Started
>>>>Snapshot Count: 0
>>>>Number of Bricks: 7 x (2 + 1) = 21
>>>>Transport-type: tcp
>>>>Bricks:
>>>>Brick1: 10.0.6.100:/gluster/brick1/brick
>>>>Brick2: 10.0.6.101:/gluster/brick1/brick
>>>>Brick3: 10.0.6.102:/gluster/arbrick1/brick (arbiter)
>>>>Brick4: 10.0.6.100:/gluster/brick2/brick
>>>>Brick5: 10.0.6.101:/gluster/brick2/brick
>>>>Brick6: 10.0.6.102:/gluster/arbrick2/brick (arbiter)
>>>>Brick7: 10.0.6.100:/gluster/brick3/brick
>>>>Brick8: 10.0.6.101:/gluster/brick3/brick
>>>>Brick9: 10.0.6.102:/gluster/arbrick3/brick (arbiter)
>>>>Brick10: 10.0.6.100:/gluster/brick4/brick
>>>>Brick11: 10.0.6.101:/gluster/brick4/brick
>>>>Brick12: 10.0.6.102:/gluster/arbrick4/brick (arbiter)
>>>>Brick13: 10.0.6.100:/gluster/brick5/brick
>>>>Brick14: 10.0.6.101:/gluster/brick5/brick
>>>>Brick15: 10.0.6.102:/gluster/arbrick5/brick (arbiter)
>>>>Brick16: 10.0.6.100:/gluster/brick6/brick
>>>>Brick17: 10.0.6.101:/gluster/brick6/brick
>>>>Brick18: 10.0.6.102:/gluster/arbrick6/brick (arbiter)
>>>>Brick19: 10.0.6.100:/gluster/brick7/brick
>>>>Brick20: 10.0.6.101:/gluster/brick7/brick
>>>>Brick21: 10.0.6.102:/gluster/arbrick7/brick (arbiter)
>>>>Options Reconfigured:
>>>>cluster.min-free-disk: 50GB
>>>>performance.strict-write-ordering: off
>>>>performance.strict-o-direct: off
>>>>nfs.disable: off
>>>>performance.readdir-ahead: on
>>>>transport.address-family: inet
>>>>performance.cache-size: 1GB
>>>>features.shard: on
>>>>features.shard-block-size: 5GB
>>>>server.event-threads: 8
>>>>server.outstanding-rpc-limit: 128
>>>>storage.owner-uid: 36
>>>>storage.owner-gid: 36
>>>>performance.quick-read: off
>>>>performance.read-ahead: off
>>>>performance.io-cache: off
>>>>performance.stat-prefetch: on
>>>>cluster.eager-lock: enable
>>>>network.remote-dio: enable
>>>>cluster.quorum-type: auto
>>>>cluster.server-quorum-type: server
>>>>cluster.data-self-heal-algorithm: full
>>>>performance.flush-behind: off
>>>>performance.write-behind-window-size: 8MB
>>>>client.event-threads: 8
>>>>server.allow-insecure: on
>>>>
>>>>
>>>>Client version:
>>>>[root at kvm573 ~]# gluster --version
>>>>glusterfs 3.12.5
>>>>
>>>>
>>>>Thanks!
>>>>
>>>>- Ian
>>>>
>>>>
>>>>_______________________________________________
>>>>Gluster-users mailing list
>>>>Gluster-users at gluster.org
>>>>http://lists.gluster.org/mailman/listinfo/gluster-users 
>>>><http://lists.gluster.org/mailman/listinfo/gluster-users>
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gluster.org/pipermail/gluster-users/attachments/20180403/922825ce/attachment.html>

More information about the Gluster-users mailing list