Hi Jan,
I’ll take a look at all of those things and report back (hopefully :))
I did try setting all of my OSDs to writethrough instead of writeback on the
controller, which was significantly more consistent in performance (from
1100MB/s down to 300MB/s, but still occasionally dropping to 0MB/s). Still
plenty of blocked ops.
I was wondering if not-so-nicely failing OSD(s) might be the cause. My
controller (PERC H730 Mini) seems frustratingly terse with SMART information,
but at least one disk has a “Non-medium error count” of over 20,000..
I’ll try disabling offloads as well.
Thanks much for the suggestions!
Cheers,
Lincoln
> On Sep 9, 2015, at 3:59 AM, Jan Schermer <j...@schermer.cz> wrote:
>
> Just to recapitulate - the nodes are doing "nothing" when it drops to zero?
> Not flushing something to drives (iostat)? Not cleaning pagecache (kswapd and
> similiar)? Not out of any type of memory (slab, min_free_kbytes)? Not network
> link errors, no bad checksums (those are hard to spot, though)?
>
> Unless you find something I suggest you try disabling offloads on the NICs
> and see if the problem goes away.
>
> Jan
>
>> On 08 Sep 2015, at 18:26, Lincoln Bryant <linco...@uchicago.edu> wrote:
>>
>> For whatever it’s worth, my problem has returned and is very similar to
>> yours. Still trying to figure out what’s going on over here.
>>
>> Performance is nice for a few seconds, then goes to 0. This is a similar
>> setup to yours (12 OSDs per box, Scientific Linux 6, Ceph 0.94.3, etc)
>>
>> 384 16 29520 29504 307.287 1188 0.0492006 0.208259
>> 385 16 29813 29797 309.532 1172 0.0469708 0.206731
>> 386 16 30105 30089 311.756 1168 0.0375764 0.205189
>> 387 16 30401 30385 314.009 1184 0.036142 0.203791
>> 388 16 30695 30679 316.231 1176 0.0372316 0.202355
>> 389 16 30987 30971 318.42 1168 0.0660476 0.200962
>> 390 16 31282 31266 320.628 1180 0.0358611 0.199548
>> 391 16 31568 31552 322.734 1144 0.0405166 0.198132
>> 392 16 31857 31841 324.859 1156 0.0360826 0.196679
>> 393 16 32090 32074 326.404 932 0.0416869 0.19549
>> 394 16 32205 32189 326.743 460 0.0251877 0.194896
>> 395 16 32302 32286 326.897 388 0.0280574 0.194395
>> 396 16 32348 32332 326.537 184 0.0256821 0.194157
>> 397 16 32385 32369 326.087 148 0.0254342 0.193965
>> 398 16 32424 32408 325.659 156 0.0263006 0.193763
>> 399 16 32445 32429 325.054 84 0.0233839 0.193655
>> 2015-09-08 11:22:31.940164 min lat: 0.0165045 max lat: 67.6184 avg lat:
>> 0.193655
>> sec Cur ops started finished avg MB/s cur MB/s last lat avg lat
>> 400 16 32445 32429 324.241 0 - 0.193655
>> 401 16 32445 32429 323.433 0 - 0.193655
>> 402 16 32445 32429 322.628 0 - 0.193655
>> 403 16 32445 32429 321.828 0 - 0.193655
>> 404 16 32445 32429 321.031 0 - 0.193655
>> 405 16 32445 32429 320.238 0 - 0.193655
>> 406 16 32445 32429 319.45 0 - 0.193655
>> 407 16 32445 32429 318.665 0 - 0.193655
>>
>> needless to say, very strange.
>>
>> —Lincoln
>>
>>
>>> On Sep 7, 2015, at 3:35 PM, Vickey Singh <vickey.singh22...@gmail.com>
>>> wrote:
>>>
>>> Adding ceph-users.
>>>
>>> On Mon, Sep 7, 2015 at 11:31 PM, Vickey Singh <vickey.singh22...@gmail.com>
>>> wrote:
>>>
>>>
>>> On Mon, Sep 7, 2015 at 10:04 PM, Udo Lembke <ulem...@polarzone.de> wrote:
>>> Hi Vickey,
>>> Thanks for your time in replying to my problem.
>>>
>>> I had the same rados bench output after changing the motherboard of the
>>> monitor node with the lowest IP...
>>> Due to the new mainboard, I assume the hw-clock was wrong during startup.
>>> Ceph health show no errors, but all VMs aren't able to do IO (very high
>>> load on the VMs - but no traffic).
>>> I stopped the mon, but this don't changed anything. I had to restart all
>>> other mons to get IO again. After that I started the first mon also (with
>>> the right time now) and all worked fine again...
>>>
>>> Thanks i will try to restart all OSD / MONS and report back , if it solves
>>> my problem
>>>
>>> Another posibility:
>>> Do you use journal on SSDs? Perhaps the SSDs can't write to garbage
>>> collection?
>>>
>>> No i don't have journals on SSD , they are on the same OSD disk.
>>>
>>>
>>>
>>> Udo
>>>
>>>
>>> On 07.09.2015 16:36, Vickey Singh wrote:
>>>> Dear Experts
>>>>
>>>> Can someone please help me , why my cluster is not able write data.
>>>>
>>>> See the below output cur MB/S is 0 and Avg MB/s is decreasing.
>>>>
>>>>
>>>> Ceph Hammer 0.94.2
>>>> CentOS 6 (3.10.69-1)
>>>>
>>>> The Ceph status says OPS are blocked , i have tried checking , what all i
>>>> know
>>>>
>>>> - System resources ( CPU , net, disk , memory ) -- All normal
>>>> - 10G network for public and cluster network -- no saturation
>>>> - Add disks are physically healthy
>>>> - No messages in /var/log/messages OR dmesg
>>>> - Tried restarting OSD which are blocking operation , but no luck
>>>> - Tried writing through RBD and Rados bench , both are giving same
>>>> problemm
>>>>
>>>> Please help me to fix this problem.
>>>>
>>>> # rados bench -p rbd 60 write
>>>> Maintaining 16 concurrent writes of 4194304 bytes for up to 60 seconds or
>>>> 0 objects
>>>> Object prefix: benchmark_data_stor1_1791844
>>>> sec Cur ops started finished avg MB/s cur MB/s last lat avg lat
>>>> 0 0 0 0 0 0 - 0
>>>> 1 16 125 109 435.873 436 0.022076 0.0697864
>>>> 2 16 139 123 245.948 56 0.246578 0.0674407
>>>> 3 16 139 123 163.969 0 - 0.0674407
>>>> 4 16 139 123 122.978 0 - 0.0674407
>>>> 5 16 139 123 98.383 0 - 0.0674407
>>>> 6 16 139 123 81.9865 0 - 0.0674407
>>>> 7 16 139 123 70.2747 0 - 0.0674407
>>>> 8 16 139 123 61.4903 0 - 0.0674407
>>>> 9 16 139 123 54.6582 0 - 0.0674407
>>>> 10 16 139 123 49.1924 0 - 0.0674407
>>>> 11 16 139 123 44.7201 0 - 0.0674407
>>>> 12 16 139 123 40.9934 0 - 0.0674407
>>>> 13 16 139 123 37.8401 0 - 0.0674407
>>>> 14 16 139 123 35.1373 0 - 0.0674407
>>>> 15 16 139 123 32.7949 0 - 0.0674407
>>>> 16 16 139 123 30.7451 0 - 0.0674407
>>>> 17 16 139 123 28.9364 0 - 0.0674407
>>>> 18 16 139 123 27.3289 0 - 0.0674407
>>>> 19 16 139 123 25.8905 0 - 0.0674407
>>>> 2015-09-07 15:54:52.694071min lat: 0.022076 max lat: 0.46117 avg lat:
>>>> 0.0674407
>>>> sec Cur ops started finished avg MB/s cur MB/s last lat avg lat
>>>> 20 16 139 123 24.596 0 - 0.0674407
>>>> 21 16 139 123 23.4247 0 - 0.0674407
>>>> 22 16 139 123 22.36 0 - 0.0674407
>>>> 23 16 139 123 21.3878 0 - 0.0674407
>>>> 24 16 139 123 20.4966 0 - 0.0674407
>>>> 25 16 139 123 19.6768 0 - 0.0674407
>>>> 26 16 139 123 18.92 0 - 0.0674407
>>>> 27 16 139 123 18.2192 0 - 0.0674407
>>>> 28 16 139 123 17.5686 0 - 0.0674407
>>>> 29 16 139 123 16.9628 0 - 0.0674407
>>>> 30 16 139 123 16.3973 0 - 0.0674407
>>>> 31 16 139 123 15.8684 0 - 0.0674407
>>>> 32 16 139 123 15.3725 0 - 0.0674407
>>>> 33 16 139 123 14.9067 0 - 0.0674407
>>>> 34 16 139 123 14.4683 0 - 0.0674407
>>>> 35 16 139 123 14.0549 0 - 0.0674407
>>>> 36 16 139 123 13.6645 0 - 0.0674407
>>>> 37 16 139 123 13.2952 0 - 0.0674407
>>>> 38 16 139 123 12.9453 0 - 0.0674407
>>>> 39 16 139 123 12.6134 0 - 0.0674407
>>>> 2015-09-07 15:55:12.697124min lat: 0.022076 max lat: 0.46117 avg lat:
>>>> 0.0674407
>>>> sec Cur ops started finished avg MB/s cur MB/s last lat avg lat
>>>> 40 16 139 123 12.2981 0 - 0.0674407
>>>> 41 16 139 123 11.9981 0 - 0.0674407
>>>>
>>>>
>>>>
>>>>
>>>> cluster 86edf8b8-b353-49f1-ab0a-a4827a9ea5e8
>>>> health HEALTH_WARN
>>>> 1 requests are blocked > 32 sec
>>>> monmap e3: 3 mons at
>>>> {stor0111=10.100.1.111:6789/0,stor0113=10.100.1.113:6789/0,stor011
>>>> 5=10.100.1.115:6789/0}
>>>> election epoch 32, quorum 0,1,2 stor0111,stor0113,stor0115
>>>> osdmap e19536: 50 osds: 50 up, 50 in
>>>> pgmap v928610: 2752 pgs, 9 pools, 30476 GB data, 4183 kobjects
>>>> 91513 GB used, 47642 GB / 135 TB avail
>>>> 2752 active+clean
>>>>
>>>>
>>>> Tried using RBD
>>>>
>>>>
>>>> # dd if=/dev/zero of=file1 bs=4K count=10000 oflag=direct
>>>> 10000+0 records in
>>>> 10000+0 records out
>>>> 40960000 bytes (41 MB) copied, 24.5529 s, 1.7 MB/s
>>>>
>>>> # dd if=/dev/zero of=file1 bs=1M count=100 oflag=direct
>>>> 100+0 records in
>>>> 100+0 records out
>>>> 104857600 bytes (105 MB) copied, 1.05602 s, 9.3 MB/s
>>>>
>>>> # dd if=/dev/zero of=file1 bs=1G count=1 oflag=direct
>>>> 1+0 records in
>>>> 1+0 records out
>>>> 1073741824 bytes (1.1 GB) copied, 293.551 s, 3.7 MB/s
>>>> ]#
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ceph-users mailing list
>>>>
>>>> ceph-users@lists.ceph.com
>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>>
>>>
>>>
>>> _______________________________________________
>>> ceph-users mailing list
>>> ceph-users@lists.ceph.com
>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>
>> _______________________________________________
>> ceph-users mailing list
>> ceph-users@lists.ceph.com
>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>
_______________________________________________
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
