PVE 7.4-17 Memory Always Full

[Mulyadi Nukuhaly]

Hi Everyone.

Hopefully you are all well today.

I have a case where the memory utilization on my PVE 7.4-17 is always full (consume arround 95%-96% memory) as in the capture below :



But the memory utilization at the OS level is not full (only consume arround 50% memory) :



Have you ever experienced abotu this ? Why PVE 7.4-17 consume memory always full and diferent from OS level ?

If so, please give me some guidance to solve the problem.

Thank You.

Best Regards,
Mulyadi Nukuhaly

 

[Folke]

Hi,
what you are seeing is most likely the zfs arc. The arc is in concept similar to the native file system cache, but due to technical limitations it shows up as normal application memory and is therefor included in Proxmox VEs memory reporting. Htop explicitly subtracts the current size of the arc and displays it as cache instead.
You can look up the current size of the arc with the arcstat command, it's the value under size:

    time  read  ddread  ddh%  dmread  dmh%  pread  ph%   size      c  avail
09:35:39     0       0     0       0     0      0    0    12G    12G   100G

When more memory is needed by other application, the arc will be reduced, but there might be circumstances where the memory is needed faster than it's needed, in that case you can tweak the arc settings [0].

On a different note, you should definitely update your systems while you are at it. Proxmox VE 7 will reach its end of life in just a couple of days, after that there is no guarantee for security updates and similar [1].

[0] https://pve.proxmox.com/wiki/ZFS_on_Linux#sysadmin_zfs_limit_memory_usage
[1] https://forum.proxmox.com/threads/proxmox-ve-support-lifecycle.35755/