> Op 10 jan. 2014 om 18:49 heeft "Steffen Thorhauer" 
> <[email protected]> het volgende geschreven:
> 
>> On 01/10/2014 01:21 PM, Ирек Фасихов wrote:
>> You need to use VirtIO.
>> 
>>    <target dev='vdb' bus='virtio'/>
> with this parameter ist not a real performance increase:
>  dd if=/dev/zero of=zerofile-2 bs=1G count=8
> 8+0 records in
> 8+0 records out
> 8589934592 bytes (8.6 GB) copied, 73.8425 s, 116 MB/s
> 
> and reading:
> 
> trompete@multius:~$ dd if=zerofile-2 of=/dev/null bs=1G count=8
> 8+0 records in
> 8+0 records out
> 8589934592 bytes (8.6 GB) copied, 429.528 s, 20.0 MB/s
> 

What happens if you increase the read_ahead_kb value for the device to 4096k. 
That is inside the guest.

Wido

> Thanks,
>   Steffen
> -- 
> ______________________________________________________________________
> Steffen Thorhauer
> 
> Department of Technichal and Business Information Systems (ITI)
> Faculty of Computer Science (FIN)
>   Otto von Guericke University Magdeburg
> Universitaetsplatz 2
> 39106 Magdeburg, Germany
> 
> phone: 0391 67 52996
> fax: 0391 67 12341
> email: [email protected]
> url: http://wwwiti.cs.uni-magdeburg.de/~thorhaue        
> _______________________________________________
> 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

Reply via email to