ARC

[Stereoscope]

When installing Proxmox, you can set "Arc max size".

In the documentation it says "ZFS uses 50 % of the host memory for the Adaptive Replacement Cache (ARC) by default. For new installations starting with Proxmox VE 8.1, the ARC usage limit will be set to 10 % of the installed physical memory, clamped to a maximum of 16 GiB."

Is it just me or is this written in a nonsensical way? It uses 50% of host memory yet at install it defaults to 10% of sys RAM with a max of 16GiB?

Just trying to figure out how it works to know what to set during install.

 

[leesteken]

Is it just me or is this written in a nonsensical way? It uses 50% of host memory yet at install it defaults to 10% of sys RAM with a max of 16GiB?

ZFS is not Proxmox specific and therefore has its own documentation and default sizes. The text might indeed be written a little more clearly (and more from a Proxmox point of view).
The ZFS default (and Proxmox default before 8.1) is 50%. The Proxmox default since 8.1 is 10% (with a maximum 16GB).

 

[Stereoscope]

OH! I think I get it now thanks. It even says ZFS as the first word. Ok now it's clear.