On Thu, Jun 25, 2020 at 4:42 AM Donald Wilde <dwilde1 at gmail.com> wrote:
> On 6/24/20, Kevin Oberman <rkoberman at gmail.com> wrote:
> > 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
>
> I was continuing to reference it because its 'incorrect results'
might
> flag where we need to see things working. When 'top' shows the
right
> results, we've fixed the right thing.
>
> >> 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.
>
> Here's what I see immediately following shutdown -r and boot:
>
> Device 1K-blocks Used Avail Capacity
> /dev/ada0s1b 67108864 0 67108864 0%
>
> >>
> >> >>> 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.
>
> Thanks again, Greg!
>
> >>
> > 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
>
> Thanks, Kevin! My laptop's BIOS is old enough that it balked when I
> tried to boot from a GPT setup of 12.1R. One Of These Days I'll fix
> that but the MBR works and I needed to move on.
>
> We'll get there! :D
>
I think a lot of people miss the point that the fact that gpart was written
primarily to provide support GPT partitioning, it also supports MBR and
bsdlabel is really obsolete. gpart(8) supports 7 different partitioning
schemes including the old RAW scheme, GPT and MBR. I still have an MBR disk
on my near decade old laptop and I use gpart on it.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman at gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683