KSM sharing

[Eric_D]

Hi,

I have a few VM and CT on my server, mostly under Ubuntu 18.04, and my KSM sharing always show "0B".

Do you know why ?

 

[fireon]

Hi,

I have a few VM and CT on my server, mostly under Ubuntu 18.04, and my KSM sharing always show "0B".

Do you know why ?

Normaly this feature need 3 to 5 days, depending on shared data. But it works here on us sever. The service is running?

 

[Eric_D]

Yes, service is running :

root@pve:~# systemctl status ksmtuned.service
● ksmtuned.service - Kernel Samepage Merging (KSM) Tuning Daemon
   Loaded: loaded (/lib/systemd/system/ksmtuned.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2019-04-15 21:47:00 CEST; 4 days ago
  Process: 987 ExecStart=/usr/sbin/ksmtuned (code=exited, status=0/SUCCESS)
 Main PID: 1033 (ksmtuned)
    Tasks: 2 (limit: 4915)
   Memory: 11.1M
      CPU: 1min 59.171s
   CGroup: /system.slice/ksmtuned.service
           ├─1033 /bin/bash /usr/sbin/ksmtuned
           └─6115 sleep 60

Apr 15 21:47:00 pve systemd[1]: Starting Kernel Samepage Merging (KSM) Tuning Daemon...
Apr 15 21:47:00 pve systemd[1]: Started Kernel Samepage Merging (KSM) Tuning Daemon.

Server and VM / CT are up for 4 days

 

[LnxBil]

AFAIK it'll only be triggered if the ram is sufficient full and also independent of the time.

I updated our cluster the last week and the KSM directly kicks in on a freshly updated node while moving a lot of machines to that node.

 

[fireon]

Works here, and Memory is not full.

 

[LnxBil]

KSM starts if you have less than 20% of your memory free. It is stated in [1] and the explanation is given by @dietmar in [2].

[1] https://pve.proxmox.com/mediawiki/index.php?title=KSM&redirect=no#KSM_in_action
[2] https://forum.proxmox.com/threads/solved-ksm-sharing.17794/#post-90575

 

[aychprox]

uncomment KSM_THRES_COEF in /etc/ksmtuned.conf and set your value.
reboot or restart ksmtuned service and wait for a while, you should see the changes.