Proxmox/pve-docs
5
0
Fork 0
mirror of git://git.proxmox.com/git/pve-docs.git synced 2025-02-02 09:47:07 +03:00
Code Releases Activity

local-zfs: mention zfs_arc_max clamping by the installer

Browse Source 
This was forgotten to be updated when it changed it the installer and
now reported in the forum [0] that the docs are a bit outdated in this
regard.

[0] https://forum.proxmox.com/threads/hat-proxmox-8-neue-zfs_arc_max-settings.142754/

Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>
This commit is contained in:
Christoph Heiss 2024-03-05 13:13:00 +01:00 committed by Thomas Lamprecht
parent c6d5bae84a
commit 2172bbb2be
1 changed files with 12 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
local-zfs.adoc
View File

@ -570,11 +570,16 @@ Limit ZFS Memory Usage
~~~~~~~~~~~~~~~~~~~~~~
ZFS uses '50 %' of the host memory for the **A**daptive **R**eplacement
**C**ache (ARC) by default. Allocating enough memory for the ARC is crucial for
IO performance, so reduce it with caution. As a general rule of thumb, allocate
at least +2 GiB Base + 1 GiB/TiB-Storage+. For example, if you have a pool with
+8 TiB+ of available storage space then you should use +10 GiB+ of memory for
the ARC.
**C**ache (ARC) by default. For new installations starting with {pve} 8.1, the
ARC usage limit will be set to '10 %' of the installed physical memory, clamped
to a maximum of +16 GiB+. This value is written to `/etc/modprobe.d/zfs.conf`.
Allocating enough memory for the ARC is crucial for IO performance, so reduce it
with caution. As a general rule of thumb, allocate at least +2 GiB Base + 1
GiB/TiB-Storage+. For example, if you have a pool with +8 TiB+ of available
storage space then you should use +10 GiB+ of memory for the ARC.
ZFS also enforces a minimum value of +64 MiB+.
You can change the ARC usage limit for the current boot (a reboot resets this
change again) by writing to the +zfs_arc_max+ module parameter directly:
@ -583,8 +588,8 @@ change again) by writing to the +zfs_arc_max+ module parameter directly:
echo "$[10 * 1024*1024*1024]" >/sys/module/zfs/parameters/zfs_arc_max
----
To *permanently change* the ARC limits, add the following line to
`/etc/modprobe.d/zfs.conf`:
To *permanently change* the ARC limits, add (or change if already present) the
following line to `/etc/modprobe.d/zfs.conf`:
--------
options zfs zfs_arc_max=8589934592