[Lustre-discuss] Lustre client error

Cliff White cliffw at whamcloud.com
Tue Feb 15 16:25:41 PST 2011 

you can use lfs find or lfs getstripe to identify where files are.
If you move the files out and move them back, the QOS policy should
re-distribute them evenly, but it very much depends. If you have clients
using a stripe count of 1,
a single large file can fill up one OST.
df on the client reports space for the entire filesystem, df on the OSS
reports space for the targets
attached to that server, so yes the results will be different.
cliffw

On Tue, Feb 15, 2011 at 4:09 PM, Jagga Soorma <jagga13 at gmail.com> wrote:

> This OST is 100% now with only 12GB remaining and something is actively
> writing to this volume.  What would be the appropriate thing to do in this
> scenario?  If I set this to read only on the mds then some of my clients
> start hanging up.
>
> Should I be running "lfs find -O OST_UID /lustre" and then move the files
> out of this filesystem and re-add them back?  But then there is no gurantee
> that they will not be written to this specific OST.
>
> Any help would be greately appreciated.
>
> Thanks,
> -J
>
>
> On Tue, Feb 15, 2011 at 3:05 PM, Jagga Soorma <jagga13 at gmail.com> wrote:
>
>> I might be looking at the wrong OST.  What is the best way to map the
>> actual /dev/mapper/mpath[X] to what OST ID is used for that volume?
>>
>> Thanks,
>> -J
>>
>>
>> On Tue, Feb 15, 2011 at 3:01 PM, Jagga Soorma <jagga13 at gmail.com> wrote:
>>
>>> Also, it looks like the client is reporting a different %used compared to
>>> the oss server itself:
>>>
>>> client:
>>> reshpc101:~ # lfs df -h | grep -i 0007
>>> reshpcfs-OST0007_UUID      2.0T      1.7T    202.7G   84%
>>> /reshpcfs[OST:7]
>>>
>>> oss:
>>> /dev/mapper/mpath7    2.0T  1.9T   40G  98% /gnet/lustre/oss02/mpath7
>>>
>>> Here is how the data seems to be distributed on one of the OSS's:
>>> --
>>> /dev/mapper/mpath5    2.0T  1.2T  688G  65% /gnet/lustre/oss02/mpath5
>>> /dev/mapper/mpath6    2.0T  1.7T  224G  89% /gnet/lustre/oss02/mpath6
>>> /dev/mapper/mpath7    2.0T  1.9T   41G  98% /gnet/lustre/oss02/mpath7
>>> /dev/mapper/mpath8    2.0T  1.3T  671G  65% /gnet/lustre/oss02/mpath8
>>> /dev/mapper/mpath9    2.0T  1.3T  634G  67% /gnet/lustre/oss02/mpath9
>>> --
>>>
>>> -J
>>>
>>>
>>> On Tue, Feb 15, 2011 at 2:37 PM, Jagga Soorma <jagga13 at gmail.com> wrote:
>>>
>>>> I did deactivate this OST on the MDS server.  So how would I deal with a
>>>> OST filling up?  The OST's don't seem to be filling up evenly either.  How
>>>> does lustre handle a OST that is at 100%?  Would it not use this specific
>>>> OST for writes if there are other OST available with capacity?
>>>>
>>>> Thanks,
>>>> -J
>>>>
>>>>
>>>> On Tue, Feb 15, 2011 at 11:45 AM, Andreas Dilger <adilger at whamcloud.com
>>>> > wrote:
>>>>
>>>>> On 2011-02-15, at 12:20, Cliff White wrote:
>>>>> > Client situation depends on where you deactivated the OST - if you
>>>>> deactivate on the MDS only, clients should be able to read.
>>>>> >
>>>>> > What is best to do when an OST fills up really depends on what else
>>>>> you are doing at the time, and how much control you have over what the
>>>>> clients are doing and other things.  If you can solve the space issue with a
>>>>> quick rm -rf, best to leave it online, likewise if all your clients are
>>>>> trying to bang on it and failing, best to turn things off. YMMV
>>>>>
>>>>> In theory, with 1.8 the full OST should be skipped for new object
>>>>> allocations, but this is not robust in the face of e.g. a single very large
>>>>> file being written to the OST that takes it from "average" usage to being
>>>>> full.
>>>>>
>>>>> > On Tue, Feb 15, 2011 at 10:57 AM, Jagga Soorma <jagga13 at gmail.com>
>>>>> wrote:
>>>>> > Hi Guys,
>>>>> >
>>>>> > One of my clients got a hung lustre mount this morning and I saw the
>>>>> following errors in my logs:
>>>>> >
>>>>> > --
>>>>> > ..snip..
>>>>> > Feb 15 09:38:07 reshpc116 kernel: LustreError: 11-0: an error
>>>>> occurred while communicating with 10.0.250.47 at o2ib3. The ost_write
>>>>> operation failed with -28
>>>>> > Feb 15 09:38:07 reshpc116 kernel: LustreError: Skipped 4755836
>>>>> previous similar messages
>>>>> > Feb 15 09:48:07 reshpc116 kernel: LustreError: 11-0: an error
>>>>> occurred while communicating with 10.0.250.47 at o2ib3. The ost_write
>>>>> operation failed with -28
>>>>> > Feb 15 09:48:07 reshpc116 kernel: LustreError: Skipped 4649141
>>>>> previous similar messages
>>>>> > Feb 15 10:16:54 reshpc116 kernel: Lustre:
>>>>> 6254:0:(client.c:1476:ptlrpc_expire_one_request()) @@@ Request
>>>>> x1360125198261945 sent from reshpcfs-OST0005-osc-ffff8830175c8400 to NID
>>>>> 10.0.250.47 at o2ib3 1344s ago has timed out (1344s prior to deadline).
>>>>> > Feb 15 10:16:54 reshpc116 kernel: Lustre:
>>>>> reshpcfs-OST0005-osc-ffff8830175c8400: Connection to service
>>>>> reshpcfs-OST0005 via nid 10.0.250.47 at o2ib3 was lost; in progress
>>>>> operations using this service will wait for recovery to complete.
>>>>> > Feb 15 10:16:54 reshpc116 kernel: LustreError: 11-0: an error
>>>>> occurred while communicating with 10.0.250.47 at o2ib3. The ost_connect
>>>>> operation failed with -16
>>>>> > Feb 15 10:16:54 reshpc116 kernel: LustreError: Skipped 2888779
>>>>> previous similar messages
>>>>> > Feb 15 10:16:55 reshpc116 kernel: Lustre:
>>>>> 6254:0:(client.c:1476:ptlrpc_expire_one_request()) @@@ Request
>>>>> x1360125198261947 sent from reshpcfs-OST0005-osc-ffff8830175c8400 to NID
>>>>> 10.0.250.47 at o2ib3 1344s ago has timed out (1344s prior to deadline).
>>>>> > Feb 15 10:18:11 reshpc116 kernel: LustreError: 11-0: an error
>>>>> occurred while communicating with 10.0.250.47 at o2ib3. The ost_connect
>>>>> operation failed with -16
>>>>> > Feb 15 10:18:11 reshpc116 kernel: LustreError: Skipped 10 previous
>>>>> similar messages
>>>>> > Feb 15 10:20:45 reshpc116 kernel: LustreError: 11-0: an error
>>>>> occurred while communicating with 10.0.250.47 at o2ib3. The ost_connect
>>>>> operation failed with -16
>>>>> > Feb 15 10:20:45 reshpc116 kernel: LustreError: Skipped 21 previous
>>>>> similar messages
>>>>> > Feb 15 10:25:46 reshpc116 kernel: LustreError: 11-0: an error
>>>>> occurred while communicating with 10.0.250.47 at o2ib3. The ost_connect
>>>>> operation failed with -16
>>>>> > Feb 15 10:25:46 reshpc116 kernel: LustreError: Skipped 42 previous
>>>>> similar messages
>>>>> > Feb 15 10:31:43 reshpc116 kernel: Lustre:
>>>>> reshpcfs-OST0005-osc-ffff8830175c8400: Connection restored to service
>>>>> reshpcfs-OST0005 using nid 10.0.250.47 at o2ib3.
>>>>> > --
>>>>> >
>>>>> > Due to disk space issues on my lustre filesystem one of the OST's
>>>>> were full and I deactivated that OST this morning.  I thought that operation
>>>>> just puts it in a read only state and that clients can still access the data
>>>>> from that OST.  After activating this OST again the client connected again
>>>>> and was okay after this.  How else would you deal with a OST that is close
>>>>> to 100% full?  Is it okay to leave the OST active and the clients will know
>>>>> not to write data to that OST?
>>>>> >
>>>>> > Thanks,
>>>>> > -J
>>>>> >
>>>>> > _______________________________________________
>>>>> > Lustre-discuss mailing list
>>>>> > Lustre-discuss at lists.lustre.org
>>>>> > http://lists.lustre.org/mailman/listinfo/lustre-discuss
>>>>> >
>>>>> >
>>>>> > _______________________________________________
>>>>> > Lustre-discuss mailing list
>>>>> > Lustre-discuss at lists.lustre.org
>>>>> > http://lists.lustre.org/mailman/listinfo/lustre-discuss
>>>>>
>>>>>
>>>>> Cheers, Andreas
>>>>> --
>>>>> Andreas Dilger
>>>>> Principal Engineer
>>>>> Whamcloud, Inc.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
>
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