Re: ONE pg deep-scrub blocks cluster

[Bill Sharer <bsharer@xxxxxxxxxxxxxx>]

Removing osd.4 and still getting the scrub problems removes its drive 
from consideration as the culprit.  Try the same thing again for osd.16 
and then osd.28.

smartctl may not show anything out of sorts until the marginally bad 
sector or sectors finally goes bad and gets remapped.  The only hint may 
be buried in the raw read error rate, seek error rate or other error 
counts like ecc or crc errors.  The long test you are running may or may 
not show any new information.


Bill Sharer

On 07/28/2016 11:46 AM, c wrote:
> Am 2016-07-28 15:26, schrieb Bill Sharer:
> > I suspect the data for one or more shards on this osd's underlying
> > filesystem has a marginally bad sector or sectors.  A read from the
> > deep scrub may be causing the drive to perform repeated seeks and
> > reads of the sector until it gets a good read from the filesystem.
> > You might want to look at the SMART info on the drive or drives in the
> > RAID set to see what the error counts suggest about this.  You may
> > also be looking at a drive that's about to fail.
> >
> > Bill Sharer
>
> Hello Bill,
>
> thank you for reading and answering my eMail :)
>
> As I wrote, I have already checked the disks via "smartctl"
>
> - osd.4: http://slexy.org/view/s2LR5ncr8G
> - osd.16: http://slexy.org/view/s2LH6FBcYP
> - osd.28: http://slexy.org/view/s21Yod9dUw
>
> Now there is running a long test " smartctl --test long /dev/DISK " on 
> all disks - to be really on the safe side. This will take a while.
>
> There is no RAID used for the OSDs!
>
> I have forgot to mention that for a test I had removed (completely) 
> "osd.4" from the Cluster and did run " ceph pg deep-scrub 0.223 " 
> again with the same result (nearly all of my VMs stop working for a 
> while).
>
> - Mehmet
>
> > On 07/28/2016 08:46 AM, c wrote:
> > > Hello Ceph alikes :)
> > >
> > > i have a strange issue with one PG (0.223) combined with "deep-scrub".
> > >
> > > Always when ceph - or I manually - run a " ceph pg deep-scrub 0.223 
> > > ", this leads to many "slow/block requests" so that nearly all of my 
> > > VMs stop working for a while.
> > >
> > > This happens only to this one PG 0.223 and in combination with 
> > > deep-scrub (!). All other Placement Groups where a deep-scrub occurs 
> > > are fine. The mentioned PG also works fine when a "normal scrub" 
> > > occurs.
> > >
> > > These OSDs are involved:
> > >
> > > #> ceph pg map 0.223
> > > osdmap e7047 pg 0.223 (0.223) -> up [4,16,28] acting [4,16,28]
> > >
> > > *The LogFiles*
> > >
> > > "deep-scrub" starts @ 2016-07-28 12:44:00.588542 and takes 
> > > approximately 12 Minutes (End: 2016-07-28 12:56:31.891165)
> > > - ceph.log: http://pastebin.com/FSY45VtM
> > >
> > > I have done " ceph tell osd injectargs '--debug-osd = 5/5' " for the 
> > > related OSDs 4,16 and 28
> > >
> > > LogFile - osd.4
> > > - ceph-osd.4.log: http://slexy.org/view/s20zzAfxFH
> > >
> > > LogFile - osd.16
> > > - ceph-osd.16.log: http://slexy.org/view/s25H3Zvkb0
> > >
> > > LogFile - osd.28
> > > - ceph-osd.28.log: http://slexy.org/view/s21Ecpwd70
> > >
> > > I have checked the disks 4,16 and 28 with smartctl and could not any 
> > > issues - also there are no odd "dmesg" messages.
> > >
> > > *ceph -s*
> > >     cluster 98a410bf-b823-47e4-ad17-4543afa24992
> > >      health HEALTH_OK
> > >      monmap e2: 3 mons at 
> > > {monitor1=172.16.0.2:6789/0,monitor3=172.16.0.4:6789/0,monitor2=172.16.0.3:6789/0}
> > >             election epoch 38, quorum 0,1,2 monitor1,monitor2,monitor3
> > >      osdmap e7047: 30 osds: 30 up, 30 in
> > >             flags sortbitwise
> > >       pgmap v3253519: 1024 pgs, 1 pools, 2858 GB data, 692 kobjects
> > >             8577 GB used, 96256 GB / 102 TB avail
> > >                 1024 active+clean
> > >   client io 396 kB/s rd, 3141 kB/s wr, 55 op/s rd, 269 op/s wr
> > >
> > > This is my Setup:
> > >
> > > *Software/OS*
> > >
> > > - Jewel
> > > #> ceph tell osd.* version | grep version | uniq
> > > "version": "ceph version 10.2.2 
> > > (45107e21c568dd033c2f0a3107dec8f0b0e58374)"
> > > #> ceph tell mon.* version
> > > [...] ceph version 10.2.2 (45107e21c568dd033c2f0a3107dec8f0b0e58374)
> > >
> > > - Ubuntu 16.04 LTS on all OSD and MON Server
> > > #> uname -a
> > > Linux galawyn 4.4.0-31-generic #50-Ubuntu SMP Wed Jul 13 00:07:12 
> > > UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
> > >
> > > *Server*
> > >
> > > 3x OSD Server, each with
> > > - 2x Intel(R) Xeon(R) CPU E5-2603 v3 @ 1.60GHz ==> 12 Cores, no 
> > > Hyper-Threading
> > > - 64GB RAM
> > > - 10x 4TB HGST 7K4000 SAS2 (6GB/s) Disks as OSDs
> > > - 1x INTEL SSDPEDMD400G4 (Intel DC P3700 NVMe) as Journaling Device 
> > > for 10-12 Disks
> > > - 1x Samsung SSD 840/850 Pro only for the OS
> > >
> > > 3x MON Server
> > > - Two of them with 1x Intel(R) Xeon(R) CPU E3-1265L V2 @ 2.50GHz (4 
> > > Cores, 8 Threads)
> > > - The third one has 2x Intel(R) Xeon(R) CPU L5430  @ 2.66GHz ==> 8 
> > > Cores, no Hyper-Threading
> > > - 32 GB RAM
> > > - 1x Raid 10 (4 Disks)
> > >
> > > *Network*
> > > - Each Server and Client has an active connection @ 1x 10GB; A 
> > > second connection is also connected via 10GB but provides only a 
> > > Backup connection when the active Switch fails - no LACP possible.
> > > - We do not use Jumbo Frames yet..
> > > - Public and Cluster-Network related Ceph traffic is going through 
> > > this one active 10GB Interface on each Server.
> > >
> > > Any ideas what is going on?
> > > Can I provide more input to find a solution?
> > >
> > > _______________________________________________
> > > ceph-users mailing list
> > > ceph-users@xxxxxxxxxxxxxx
> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> >
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