ZFS ARC going high since PVE 9.1 upgrade

[fips]

Hey Community,

on last weekend I have upgraded my 2 node "cluster" from 8.x to 9.1.7.
Since saturday, monitoring is complaining that both server eat up there memory even with very little load (about 6-8 VMs with about 1-6GB on each hosts).

Today I was emptying one server, rebooted it and after a couple of hours memory is again full.
I have a feeling that ZFS ARC reserves too much of it.
Attached you can find 2 screenshot with the consumption over the whole day.

any idea or suggestion for solving that issue is highly appreciated

Thanks
Stefan

 

[Impact]

Read here: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#sysadmin_zfs_limit_memory_usage
And here: https://gist.github.com/Impact123/3dbd7e0ddaf47c5539708a9cbcaab9e3#update-zfs-arc-size

 

[_gabriel]

Check/adjust your
/etc/modprobe.d/zfs.conf
then
update-initramfs -u -k all