Slow VM's

[Treello]

Hello,

I have used the search utility and researched this quite a bit but still am unable to nail down just why my VMs seem so slow. Installing CentOS 6.6 in a VM it seems very very sluggish.

My box specs are 2 x Xeon X5667
32 Gigs for DDR3
PERC H700 Raid Card
RAID 10 with 4 x 146 GB 15k RPM SAS 6.0 Gbp/s

at current time i can't stop all my VM's to perform a pveperf but this is what i have with 2 vms running

root@***:~# pveperf
CPU BOGOMIPS: 97886.96
REGEX/SECOND: 1234159
HD SIZE: 9.84 GB (/dev/mapper/pve-root)
BUFFERED READS: 296.74 MB/sec
AVERAGE SEEK TIME: 3.29 ms
FSYNCS/SECOND: 3861.66
DNS EXT: 49.61 ms
DNS INT: 3.76 ms (****)

root@***:~# pveperf
CPU BOGOMIPS: 97886.96
REGEX/SECOND: 1253641
HD SIZE: 9.84 GB (/dev/mapper/pve-root)
BUFFERED READS: 278.34 MB/sec
AVERAGE SEEK TIME: 3.40 ms
FSYNCS/SECOND: 3415.58
DNS EXT: 47.18 ms
DNS INT: 9.69 ms (****)



For the VM hardware it doesn't seem to matter how much ram or processors i give em. Using RAW format, virtio interface, with write-thorugh for cache. We do have the directorys / and the vz one remounted with noatime which did help some. Any suggestions would be mighty appreciated.

 

[udo]

Hi,
pveperf-values looks not bad - but this shows only read values. Nevertheless it's looks not that the write-performance is the problem (because of fsyncs/second).

Can you post the VM-config from the sluggish centos VM?

And also additional following output:

cat /etc/pve/storage.cfg
mount
pveversion -v
lsmod | grep kvm

if you start an live-distro in an VM like grml, does the speed looks also bad?

Udo