Re: pkg upgrade, vfs.zfs.arc.free_target, vfs.zfs.arc.sys_free, vm.pageout_oom_seq

From: Graham Perrin <grahamperrin_at_gmail.com>
Date: Sun, 31 Aug 2025 19:01:55 UTC 
On 31/08/2025 09:38, Mark Millard wrote:

> …
>
> So 4 GiBytyes of RAM is insufficient, even with use of: vm.pageout_oom_seq=120
>
> Note: In this context increases is not going to help: it is way too little RAM
> for pkg. (I was observing via top at the time.)
>
> If pkg continues to require such RAM+SWAP usage, FreeBSD is going to end up
> requiring more than, say, 5 GiBytes of RAM+SWAP, even for UFS contexts.
>
>> …
>
> For reference, see:
>
> https://lists.freebsd.org/archives/freebsd-pkgbase/2025-August/000804.html
>
> with details of my test context (where swap was in use).


Interesting.

Here, with faster storage for a new guest, 1,024 MB base memory was 
enough – for both UFS and ZFS – as outlined below.

----


VirtualBox
bidirectional shared clipboard
1 GB memory
EFI
four processors
PAE/NX
VBoxSVGA
FreeBSD-14.3-RELEASE-amd64-dvd1.iso
disable host I/O cache
vm.pageout_oom_seq=120
UFS
3 G swap
install all components
pkbasify conversion before first boot (519 packages)
first boot
vm.pageout_oom_seq=120
pkg install -Fy firefox gitup htop hw-probe kde lsblk lynx nano pciutils 
plasma6-sddm-kcm roxterm sddm stressdisk uclcmd usbutils 
virtualbox-ose-additions xfce xorg
pkg install -Uy firefox gitup htop hw-probe kde lsblk lynx nano pciutils 
plasma6-sddm-kcm roxterm sddm stressdisk uclcmd usbutils 
virtualbox-ose-additions xfce xorg
pkg upgrade -fFqy
pkg upgrade -fUy
1353 packages
2601 steps
success
vm.pageout_oom_seq=12
pkg upgrade -fUy
success

----


The same with ZFS. Success with, then without, the 
increased vm.pageout_oom_seq