On Aug 30, 2025, at 09:58, Graham Perrin <grahamper...@gmail.com> wrote:
> On 30/08/2025 14:50, Mark Millard wrote:
>
>> … efficient ZFS use. …
>
>
> Thanks, I should add that efficiency is not my objective with these tests.
>
> I'd like the outcomes to include pkg upgrade tips for end users who, for
> various reasons, find themselves with the benefits of ZFS (not least, bectl
> for boot environments) on systems that are constrained (e.g. 4 GB memory and
> limited free space on a HDD).
>
> I sense that vm.pageout_oom_seq might be the sanest approach, in cases where
> hardware constraints are relatively severe. I'm open to alternative
> suggestions.
It would appear that RAM==4GiBytes without SWAP would not be
generally supported by pkg as stands. Testing hw.physmem="4G"
without SWAP . . .
OOM KILLS result:
# pkg upgrade -rFreeBSD-ports -fUy
Checking for upgrades (1485 candidates): 100%
Processing candidates (1485 candidates): 100%
Checking integrity...Child process pid=2219 terminated abnormally: Killed
dmesg -a shows:
pid 2219 (pkg), jid 0, uid 0, was killed: failed to reclaim memory
Aug 31 01:28:47 FBSDamd64S kernel: pid 2219 (pkg), jid 0, uid 0, was killed:
failed to reclaim memory
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.
> In the past I could be quite careless about untimely interruptions to
> upgrades ("simply re-run the pkg command, maybe more than once, until it
> found nothing more to upgrade."). Nowadays there's a greater risk of an
> awkward problem following an untimely interruption. I don't mind the
> awkwardness (I know how to dig myself out of a hole); other users might be
> less forgiving.
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).
===
Mark Millard
marklmi at yahoo.com
