I/O Performance KVM

[MasterTH]

Hi,

i got a problem.
I've two KVM-Maschines running in pve1.5. But they just make 2MB read/write to the disk.

the OpenVZ-Maschines are pretty fast, 80MB/s.


Is there a known bug or something else i can try?

hdparm -tT /dev/md0

/dev/md0:
Timing cached reads: 14724 MB in 1.99 seconds = 7411.14 MB/sec
Timing buffered disk reads: 302 MB in 3.00 seconds = 100.59 MB/sec


pveperf
CPU BOGOMIPS: 42557.97
REGEX/SECOND: 460020
HD SIZE: 19.38 GB (/dev/md1)
BUFFERED READS: 130.82 MB/sec
AVERAGE SEEK TIME: 70.76 ms
FSYNCS/SECOND: 76.70
DNS EXT: 63.78 ms
DNS INT: 18.82 ms



Thanks

 

[udo]

Hi,
softwareraid are not supported, so i think you must try yourself - but perhaps other peoples with sw-raids know a solution.

Do you use raw-format? if not, you should try.
Are the clients windows-guests? If yes, use only one cpu/core.

You can also try the kvm-params cache and aio (man kvm).

Your seek-time is very bad - can you optimized it?

Udo