Re: Is it only me or is the ZFS memory usage for desktop computers uncomfortable?

[Greg Troxel <gdt%lexort.com@localhost>]

Ellie <el%horse64.org@localhost> writes:

> I understand that on a server, often it's worth sinking a lot of
> memory into ZFS for better performance.
>
> But is it only me, or is this trade-off not the same for desktops?
>
> 50% of memory less may have severe consequences on a desktop:
>
> - Many modern games that would maybe have worked via wine or a VM,
>   will no longer work since e.g. many will work with 16GB but not with
>  8GB.
>
> - Some audio software similarly may require a lot of memory to run.
>
> - Compiling many rust projects or some C++ projects will require more
>   than 8GB RAM, it would work on a 16GB RAM machine but not with ZFS.
>
> I was surprised to see that this memory usage is configurable for many
> ZFS implementations, but apparently not for NetBSD's:

More or less, the ZFS philosophy is that it's better to use RAM for
caching than not to use it.   When ZFS ARC and memory management works
the way it is designed -- and I think in 11 it does -- then when there
is memory pressure the cache shrinks.

I believe there is a lower limit below which the ARC will not shrink but
I think it's at most 1/8 of RAM, maybe lower.  There have been patches
to adjust this, but I stopped using them now that so many zfs bugs
(zfs/netbsd adapatation layer) were fixed in 11.

You say "it would work but not with ZFS".  Is that speculation, or do
you have data?

I have a desktop with ZFS and 32GB, and now with 11 it is solid and I am
not feeling like I am having ZFS problems.  (Just X/firefox/glgears
wired pages leak.).


The ZFS upstream situation seems unclear and in flux.  There is openzfs
and there is illumos.  I personally am not super worried about it.  But,
I'm much more concerned about not interacting with LLMs myself, and not
being active in a community where there's a lot of that, vs any project
that doesn't have a total ban must be fully shunned.  I'm not trying to
criticize your stance, just to say where I am, this minute.