[sheepdog-users] Object Cache Question

[Hitoshi Mitake]

At Fri, 14 Mar 2014 16:53:56 +0100,
Bastian Scholz wrote:
> 
> Ping?
> 
> Anyone has an idea or hint, while enabling
> Object Cache has this impact on performance?

Hi Bastian,

Sorry for late reply. Currently I cannot see any visible problems in
your settings. Could you add your problem as a performance issue to
our bug tracker?

https://bugs.launchpad.net/sheepdog-project/+bugs

Thanks,
Hitoshi

> 
> Cheers
> 
> Bastian
> 
> Am 2014-03-11 09:42, schrieb Bastian Scholz:
> > Hi List,
> > 
> > I try around with object cache of sheepdog in my
> > Testcluster (3 nodes, copies=3).
> > 
> > For this, I start an additional gateway sheep
> > process on one node (separated disk for cache but
> > same type as the obj disks). But when enabling
> > Object Cache, the rw performance of random 4k
> > rw drops to 1/10th of the speed without OC enabled.
> > 
> > # sheep --version
> > Sheepdog daemon version 0.7.7
> > 
> > # qemu --version
> > QEMU emulator version 1.1.2 (Debian 1.1.2+dfsg-6a)
> > 
> > # virsh --version
> > 0.9.12.3
> > 
> > qemu cache setting is none (managed by libvirt), but
> > it didnt make any noticeable difference when set to
> > writeback or writethrough...
> > 
> > # sheep /mnt/soeren/3/ -g -p 7003
> > # fio guest results
> > read : io=11612KB, bw=594415 B/s, iops=145 , runt= 20004msec
> > write: io=11804KB, bw=604243 B/s, iops=147 , runt= 20004msec
> > 
> > # sheep /mnt/soeren/3/ -g -p 7003 -w size=10G
> > # fio guest results
> > read : io=1172.0KB, bw=59934 B/s, iops=14 , runt= 20024msec
> > write: io=1256.0KB, bw=64230 B/s, iops=15 , runt= 20024msec
> > 
> > For comparison the fio results of the sheep
> > cache directory.
> > 
> > read : io=10576KB, bw=541355 B/s, iops=132 , runt= 20005msec
> > write: io=10712KB, bw=548317 B/s, iops=133 , runt= 20005msec
> > 
> > Any Ideas whats wrong? Maybe some Problems with
> > the old QEMU Version?
> > 
> > Cheers
> > Bastian
> -- 
> sheepdog-users mailing lists
> sheepdog-users at lists.wpkg.org
> http://lists.wpkg.org/mailman/listinfo/sheepdog-users