On Wed, Jun 24, 2020 at 10:30 PM Greg 'groggy' Lehey <grog at
freebsd.org>
wrote:
> On Wednesday, 24 June 2020 at 20:34:24 -0700, Donald Wilde wrote:
> > On 6/24/20, Greg 'groggy' Lehey <grog at freebsd.org>
wrote:
> >> On Wednesday, 24 June 2020 at 18:51:04 -0700, Donald Wilde wrote:
> >>> On 6/24/20, Greg 'groggy' Lehey <grog at
freebsd.org> wrote:
> >>>> On Wednesday, 24 June 2020 at 9:36:23 -0700, Donald Wilde
wrote:
> >>>>> All,
> >>>>>
> >>>>> I recently upgraded my 12-STABLE system to the latest,
and now my
> >>>>> swap subsystems aren't working. I deliberately set
up a 40GB
> >>>>> partition for swap, and when I do 'top -t' I
am only seeing 7906M
> >>>>> total.
> >>>>
> >>>> That looks suspiciously like the difference from 32 GB.
Could it be
> >>>> numeric overflow? And if so, where? What does pstat -s
say?
> >>>
> >>> Well, hi Greg! LTNT2!
> >>
> >> Indeed.
> >>
> >>> pstat -shm:
> >>>
> >>> /dev/ada0s1b 65536 (1M blocks), Used: 1.5G, Avail: 63G,
Capacity: 2%
> >>
> >> Now that's really puzzling. Why does it say 64 G when you
said 40 G,
> >> and the error from top tends to confirm it? How big is the
partition
> >> (gpart output)?
> >
> > Attached 'gpart list' output
>
> FWIW, gpart show would have done the job. But what I see there is Yet
> Another swap partition size, 66 GB. So so far we have various parts
> reporting 8 GB, 40 GB, 64 GB and 66 GB.
>
> > Reduced kern.maxswzone to 9999999. Is it decimal or unlabeled hex?
>
> It'll be decimal, but it refers to the number of swblk structures
> assigned in memory, and after reading the code I'm still not 100% in
> the clear how this relates to the size of swap, if at all.
>
> > 'top' now shows 4597M total swap.
>
> ... and 4.6 GB. 5 different sizes.
>
> You really shouldn't be relying on top for swap info. It's a third
> party program that demonstrably shows incorrect results (though I
> believe that the maintainer would be very interested to know why and
> to fix it). But pstat -s (without any further options) should show
> what the kernel thinks.
>
> >>> What else can I share to help diagnose this?
> >>
> >> Background, maybe? You say that you upgraded your system. Did
you
> >> change the swap size when you did? What were swap and RAM sizes
> >> before and after?
> >
> > Meant that I upgraded from 12.1-RELEASE to 12-STABLE. When I
> > configured the -RELEASE install, I manually messed with the MBR disk
> > partitions. This is nominally a half-TB HDD which showed up as a total
> > of 446 G available (IIRC, gpart should show it's actual size). I
did
> > auto partitioning, looked at the sizes, and manually set my partitions
> > to give me 40G of swap instead of the auto-generated size of 4G.
>
> That's really puzzling. It seems that it gave you much more than you
> asked for.
>
> Try this in single user mode: modify the size of the swap partition to
> 30 GB. I haven't used MBR partitions for years now, but I believe
> that 'bsdlabel -e' will do the trick. Just shorten the length of
the
> b partition. You may need to 'mount -u /'. If you do it right
> (check!), this won't harm any of the other partitions: it'll just
> leave 26 GB free between the swap partition and the next partition.
>
gpart(8) works just fine on MBR drives and partitions/slices and has a much
friendlier user interface. "gpart resize" is the command you want.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman at gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683