RAM issue. Much more than CT's in use

[chencho]

I have a fresh install (proxmox 7) with 128 GB RAM

Then I create 2 x CT to use MariaDB, 4 RAM each other.

1 x CT to use docker inside.

If I go to each CT, I can see MariaDB are using 1 x GB each other (2 in total) and docker CT are using 1 more = 3 GB RAM

But when I go to Server in proxmox, I see 114 GB used!!!!

Mariadb 1:



Mariadb 2:



Docker:



Server:

 

[Dunuin]

Do you use ZFS? ZFS by default is using up to 50% of the hosts total RAM for caching. You could check that by running arc_summary. And linux might cache page files too. To check that you could run free --giga and see how much used used for "buff/cache".

 

[chencho]

Yes, I'm on ZFS file system

 

[chencho]

I'm gone change max usage to 16 GB

https://linuxhint.com/configure-zfs-cache-high-speed-io/

Thanks

 

[Dunuin]

the important part is the UP TO 50% of hosts RAM. ZFS can also shrink its usage if needed for something else. So usually its no problem that ZFS uses your RAM. If you really want you could limit the ARC like described here: https://pve.proxmox.com/wiki/ZFS_on_Linux#sysadmin_zfs_limit_memory_usage
But keep in mind, unused RAM is wasted performance. Unless you run into OOM, because ZFS shrinking the ARC too slow, I wouldn't limit the ARC.

And to find out where the other 41GB went you could show us the output of free --giga.