also during writes.
I've tested it now on linux with a virtio disk-drive:
<disk type='network' device='disk'>
<driver name='qemu' type='raw'/>
<source protocol='rbd' name='rd/backup:rbd_cache=1'>
<host name='rd-c2.ceph' port='6789'/>
<host name='rd-c1.ceph' port='6789'/>
<host name='wag-c1.ceph' port='6789'/>
</source>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
</disk>
virsh console to the running VM.
Next - Write Test:
dd if=/dev/zero of=/bigfile bs=2M &
Serial console gets jerky, VM gets unresponsive. It doesn't crash, but
it's not 'healthy' either. CPU load isn't very high, it's in the waiting
state a lot:
Cpu(s): 0.0%us, 4.7%sy, 0.0%ni, 26.1%id, 68.4%wa, 0.0%hi, 0.3%si,
0.5%st
1170 root 20 0 11736 2452 556 D 8.5 0.5 0:00.80 dd
Wolfgang
On 03/11/2013 01:42 PM, Mark Nelson wrote:
> I guess first question is does the jerky mouse behavior only happen
> during reads or writes too? How is the CPU utilization in each case?
>
> Mark
>
> On 03/11/2013 01:30 AM, Wolfgang Hennerbichler wrote:
>> Let me know if I can help out with testing somehow.
>>
>> Wolfgang
>> ________________________________________
>> Von: [email protected]
>> [[email protected]]" im Auftrag von "Mark
>> Nelson [[email protected]]
>> Gesendet: Samstag, 09. März 2013 20:33
>> Bis: [email protected]
>> Betreff: Re: [ceph-users] I/O Speed Comparisons
>>
>> Thanks for all of this feedback guys! It gives us some good data to try
>> to replicate on our end. Hopefully I'll have some time next week to
>> take a look.
>>
>> Thanks!
>> Mark
>>
>> On 03/09/2013 08:14 AM, Erdem Agaoglu wrote:
>>> Mark,
>>>
>>> If it's any help, we've done a small totally unreliable benchmark on our
>>> end. For a KVM instance, we had:
>>> 260MB/s write, 200MB/s read on local SAS disks, attached as LVM LVs,
>>> 250MB/s write, 90MB/s read on RBD, 32 osds, all SATA.
>>>
>>> All sequential, a 10G network. It's more than enough currently but we'd
>>> like to improve RBD read performance.
>>>
>>> Cheers,
>>>
>>>
>>> On Sat, Mar 9, 2013 at 7:27 AM, Andrew Thrift <[email protected]
>>> <mailto:[email protected]>> wrote:
>>>
>>> Mark,
>>>
>>>
>>> I would just like to add, we too are seeing the same behavior with
>>> QEMU/KVM/RBD. Maybe it is a common symptom of high IO with this
>>> setup.
>>>
>>>
>>>
>>> Regards,
>>>
>>>
>>>
>>>
>>>
>>> Andrew
>>>
>>>
>>> On 3/8/2013 12:46 AM, Mark Nelson wrote:
>>>
>>> On 03/07/2013 05:10 AM, Wolfgang Hennerbichler wrote:
>>>
>>>
>>>
>>> On 03/06/2013 02:31 PM, Mark Nelson wrote:
>>> t
>>>
>>> If you are doing sequential reads, you may benefit by
>>> increasing the
>>> read_ahead_kb value for each device in
>>> /sys/block/<device>/queue on the
>>> OSD hosts.
>>>
>>>
>>> Thanks, that didn't really help. It seems the VM has to
>>> handle too much
>>> I/O, even the mouse-cursor is jerking over the screen when
>>> connecting
>>> via vnc. I guess this is the wrong list, but it has somehow
>>> to do with
>>> librbd in connection with kvm, as the same machine on LVM
>>> works just ok.
>>>
>>>
>>> Thanks for the heads up Wolfgang. I'm going to be looking into
>>> QEMU/KVM
>>> RBD performance in the coming weeks so I'll try to watch out
>>> for
>>> this
>>> behaviour.
>>>
>>>
>>> Wolfgang
>>> _________________________________________________
>>> ceph-users mailing list
>>> [email protected]
>>> <mailto:[email protected]>
>>> http://lists.ceph.com/__listinfo.cgi/ceph-users-ceph.__com
>>> <http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com>
>>>
>>>
>>>
>>> _________________________________________________
>>> ceph-users mailing list
>>> [email protected] <mailto:[email protected]>
>>> http://lists.ceph.com/__listinfo.cgi/ceph-users-ceph.__com
>>> <http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com>
>>>
>>>
>>>
>>>
>>> --
>>> erdem agaoglu
>>>
>>>
>>>
>>> _______________________________________________
>>> ceph-users mailing list
>>> [email protected]
>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>
>>
>> --
>> Mark Nelson
>> Performance Engineer
>> Inktank
>> _______________________________________________
>> ceph-users mailing list
>> [email protected]
>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>> _______________________________________________
>> ceph-users mailing list
>> [email protected]
>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>
>
> _______________________________________________
> ceph-users mailing list
> [email protected]
> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
--
DI (FH) Wolfgang Hennerbichler
Software Development
Unit Advanced Computing Technologies
RISC Software GmbH
A company of the Johannes Kepler University Linz
IT-Center
Softwarepark 35
4232 Hagenberg
Austria
Phone: +43 7236 3343 245
Fax: +43 7236 3343 250
[email protected]
http://www.risc-software.at
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