Re: bsdinstall: system requirements: memory/RAM: ZFS: 2048 MB for an ordinary installation plus a desktop environment

Yea, I've not seen that to be the case. ZFS isn't that big of a memory hog
these days... There are times you do need to tune the arc, but they are the
exception, not the rule.

Warner

On Tue, Sep 30, 2025 at 1:41 PM Brandon Allbery <allbery.b@gmail.com> wrote:

> FWIW my understanding is that ZFS root is such a memory hog that anything
> under 16GB is disrecommended and 32GB preferable. (I have only one
> machine that fits that constraint, and FreeBSD doesn't quite work on it
> yet.)
>
> On Tue, Sep 30, 2025 at 3:38 PM Rick Macklem <rick.macklem@gmail.com>
> wrote:
>
>> On Sun, Sep 28, 2025 at 7:59 AM Warner Losh <imp@bsdimp.com> wrote:
>> >
>> >
>> >
>> > On Sun, Sep 28, 2025, 4:47 AM Graham Perrin <grahamperrin@gmail.com>
>> wrote:
>> >>
>> >> Follow-up to <
>> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=287719#c6>
>> >>
>> >> Good news.
>> >>
>> >> 2048 MB is sufficient with root-on-ZFS for an ordinary installation
>> >> (more than base, less than all of FreeBSD-base) of 15.0-ALPHA4
>> >> plus these five non-base packages, some of which are meta:
>> >>
>> >>      kde plasma6-sddm-kcm sddm virtualbox-guest-additions xorg
>> >>
>> >> Beyond initial installations: with 4 G swap enabled, I repeatedly
>> >> tested forced reinstallation of all packages,
>> >>
>> >>      pkg upgrade -fUy
>> >>
>> >> 1077 packages, 1886 steps. Success.
>> >>
>> >> ----
>> >>
>> >> With swap disabled, which I would not recommend:
>> >>
>> >> - reinstallation failed, switch from ttyv1 to ttyv2 was
>> >>    impossible, and so on, so I attempted a shut down
>> >>    <https://i.imgur.com/RftLGMu.png>
>> >>
>> >> - shut down failed
>> >>
>> >> - following a forced stop of the computer, SDDM and the
>> >>    desktop environment were unsable (pkg issue 2441,
>> >>    second incident this morning).
>> >
>> >
>> > It's big enough to install.. but i have lxte + terminal + firefox with
>> 4 tabs open and I routinely run out of memory and swap heavily. I have a
>> 4GB Chromebook.
>> Just a wild guess, but I suspect ZFS might be eating your memory.
>> You could try something like setting:
>> vfs.zfs.arc.max to half of your ram and see what happens?
>>
>> You probably don't want to do this, but it would be interesting to
>> see what happens if you use UFS.
>> (Personally, I'd never use ZFS for a root fs, but that's just me.)
>>
>> rick
>>
>> >
>> > So one can run in 128MB for light tasks and careful kernel tuning,
>> 512MB is a more realistic minimum since it lets you install and update. But
>> for X it's flipped: you need 2G to install but closer to 4G or 8G to run a
>> complete, but on the lean side, X11 system.
>> >
>> > Warner
>> >>
>> >>
>>
>>
>
> --
> brandon s allbery kf8nh
> allbery.b@gmail.com
>