On Tue, Sep 30, 2025 at 1:18 PM Warner Losh <i...@bsdimp.com> wrote: > > > > On Tue, Sep 30, 2025 at 2:03 PM Rick Macklem <rick.mack...@gmail.com> wrote: >> >> On Tue, Sep 30, 2025 at 12:50 PM Warner Losh <i...@bsdimp.com> wrote: >> > >> > 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. >> Unfortunately, using ZFS as an NFS server seems to be an exception. >> Peter Errikson still uses 13.5 on his servers, since he doesn't find 14.n >> stable enough. >> There is this email thread: >> https://lists.freebsd.org/archives/freebsd-stable/2025-September/003126.html > > > OK. Since I no longer do NFS, I've not hit that.... I didn't figure you had hit it. I was hoping that you (or someone else reading this) might know someone willing to tackle the problem?
rick > >> >> >> I'd like to see this resolved, but I don't know enough about VM or >> ZFS's arc code >> and I have miniscule hardware, so I cannot replicate it. >> >> Btw, what is a BE? > > > BE is a boot environment. It's basically a way to switch between different > versions of the system quickly and easily, as well as offline update the > system so you don't shoot yourself in the foot by removing libc.so... Great > for both development and deployment. Worth paying the small extra memory tax > I do see with ZFS. > > Warner > >> >> rick >> >> > >> > Warner >> > >> > On Tue, Sep 30, 2025 at 1:41 PM Brandon Allbery <allber...@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.mack...@gmail.com> >> >> wrote: >> >>> >> >>> On Sun, Sep 28, 2025 at 7:59 AM Warner Losh <i...@bsdimp.com> wrote: >> >>> > >> >>> > >> >>> > >> >>> > On Sun, Sep 28, 2025, 4:47 AM Graham Perrin <grahamper...@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 >> >> allber...@gmail.com
