Hi Wido;
Thanks for fast response rbd ls -l reads all images header for its sizes
yes it makes sense you are right.

My main problem is when i refresh a rbd storage pool using virsh over
kvm(Ubuntu 14.04.5) it takes too much time then the old days and i suspect
that virsh makes "rbd ls -l" over Ceph storage so thats why i asked.

Does virsh use same "rbd ls -l" for pool refresh?

So in this case below 22 second is normal for virsh rbd pool refresh?

root@kvmt1:~# time virsh pool-refresh 01b375db-d3f5-33c1-9389-8bf226c887e8
Pool 01b375db-d3f5-33c1-9389-8bf226c887e8 refreshed


real 0m22.504s
user 0m0.012s
sys 0m0.004s

Thanks
Özhan


On Thu, Feb 9, 2017 at 11:30 AM, Wido den Hollander <[email protected]> wrote:

>
> > Op 9 februari 2017 om 9:13 schreef Özhan Rüzgar Karaman <
> [email protected]>:
> >
> >
> > Hi;
> > I am using Hammer 0.49.9 release on my Ceph Storage, today i noticed that
> > listing an rbd pool takes to much time then the old days. If i have more
> > rbd images on pool it takes much more time.
> >
>
> It is the -l flag that you are using in addition. That flag opens each RBD
> image and stats the header of it to get the size.
>
> A regular 'rbd ls' will only read the RADOS object rbd_directory, but it
> is the -l flag which causes the RBD tool to iterate over all the images and
> query their header.
>
> > My clusters health is ok and currently there is no load on the cluster.
> > Only rbd images are used to serve to vm's.
> >
> > I am sending some information below. My level.db size is also 280 mb, i
> > also compacted level.db to 40 mb size but again "rbd ls -l" output is too
> > slow.
> >
> > This timing is important for my vm deploy time to complete because when i
> > refresh a pool/datastore it takes nearly to 20 seconds or more for 350
> rbd
> > images+snapshots.
> >
> > Thanks for all help
> >
> > Regards
> > Ozhan Ruzgar
> >
> > root@mont3:/var/lib/ceph/mon/ceph-mont3/store.db# ceph -s
> >     cluster 6b1cb3f4-85e6-4b70-b057-ba7716f823cc
> >      health HEALTH_OK
> >      monmap e1: 3 mons at
> > {mont1=172.16.x.x:6789/0,mont2=172.16.x.x:6789/0,mont3=
> 172.16.x.x:6789/0}
> >             election epoch 126, quorum 0,1,2 mont1,mont2,mont3
> >      osdmap e20509: 40 osds: 40 up, 40 in
> >       pgmap v20333442: 1536 pgs, 3 pools, 235 GB data, 63442 objects
> >             700 GB used, 3297 GB / 3998 GB avail
> >                 1536 active+clean
> >   client io 0 B/s rd, 3785 kB/s wr, 314 op/s
> >
> > root@mont1:~# time rbd ls -l cst2|wc -l
> > 278
> >
> > real 0m11.970s
> > user 0m0.572s
> > sys 0m0.316s
> > root@mont1:~# time rbd ls -l cst3|wc -l
> > 15
> >
> > real 0m0.396s
> > user 0m0.020s
> > sys 0m0.032s
> > root@mont1:~# time rbd ls -l cst4|wc -l
> > 330
> >
> > real 0m16.630s
> > user 0m0.668s
> > sys 0m0.336s
> > _______________________________________________
> > ceph-users mailing list
> > [email protected]
> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>
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