KSM Problems with Proxmox 1.8

[leftcase]

Hi there,

I have recently installed Proxmox and upgraded to the 2.6.35-1-pve kernel.

I'm currently running 5 Windows XP KVM virtual machines, each with 512MB of RAM assigned, on a physical host which reports 3.85GB of Physical memory. Currently it reports 2.97GB in use.

Unfortunately I can't seem to get KSM working properly.

pveversion shows:

pve-manager: 1.8-18 (pve-manager/1.8/6070)
running kernel: 2.6.35-1-pve
proxmox-ve-2.6.35: 1.8-11
pve-kernel-2.6.32-4-pve: 2.6.32-33
pve-kernel-2.6.35-1-pve: 2.6.35-11
qemu-server: 1.1-30
pve-firmware: 1.0-11
libpve-storage-perl: 1.0-17
vncterm: 0.9-2
vzctl: 3.0.27-1pve1
vzdump: 1.2-13
vzprocps: 2.0.11-2
vzquota: 3.0.11-1
pve-qemu-kvm: 0.14.1-1
ksm-control-daemon: 1.0-6

But cat /sys/kernel/mm/ksm/run always shows 0.

I've tried echo 1 > /sys/kernel/mm/ksm/run - but the value of run seems to change automatically back to 0 again after a short while.

/etc/init.d/ksmtuned status reports

KSM control daemon is running..

Can anyone give me any tips on what to do next?

Thanks,

Chris

 

[leftcase]

Ah, KSM just seemed to enable itself.

Strangely, it didn't come on until I literally maxed out the physical memory though!

 

[l.mierzwa]

KSM tuned deamon will enable KSM only if You use >50% memory

 

[leftcase]

That's interesting, because it didn't seem to enable itself on my machine until I'd used around 80% of available physical memory.

It's running quite nicely now however, with 5 Windows XP guests each with 1GB of RAM using only 3-4GB of physical RAM on the host (and that's including memory used by Promox itself). Nice! It slows a little when rebooting guests, but I guess this is because KSM is reallocating memory pages amongst remaining hosts and the reallocating them again when it comes back up.

Chris