Date: Thu, 25 Jun 2020 07:34:46 -0700 From: Kevin Oberman <rkoberman@gmail.com> To: Donald Wilde <dwilde1@gmail.com> Cc: "Greg 'groggy' Lehey" <grog@freebsd.org>, freebsd-stable <freebsd-stable@freebsd.org> Subject: Re: swap space issues Message-ID: <CAN6yY1tChhDVQg3%2B3eEtoewP=xJDqTA06D=o1UT3gH4Pnx63kQ@mail.gmail.com> In-Reply-To: <CAEC7391v6BzfzOyt8Y8eROEhgzWH3VV67qJ9LtycB_zrnhd-qg@mail.gmail.com> References: <CAEC7391qs%2BA-jMpR1RyvR-BmnLyiksXHkQUjsGeePuEZJfMciw@mail.gmail.com> <20200625000410.GA10210@eureka.lemis.com> <CAEC7390VDxbYSY%2B4_fEaYxwdSPzbFWUVTdHw=vbAgq%2Bnmv09Vw@mail.gmail.com> <20200625025248.GB10210@eureka.lemis.com> <CAEC73938Wjb5MHvLW36PdoAy_nso-tSN51AhUYydC6qxY99pog@mail.gmail.com> <20200625052949.GC10210@eureka.lemis.com> <CAN6yY1te3ZzyY3JdhQAf4_CbD%2Bsf2sjXzU5PH63T2YV2erYS=A@mail.gmail.com> <CAEC7391v6BzfzOyt8Y8eROEhgzWH3VV67qJ9LtycB_zrnhd-qg@mail.gmail.com>
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On Thu, Jun 25, 2020 at 4:42 AM Donald Wilde <dwilde1@gmail.com> wrote: > On 6/24/20, Kevin Oberman <rkoberman@gmail.com> wrote: > > On Wed, Jun 24, 2020 at 10:30 PM Greg 'groggy' Lehey <grog@freebsd.org> > > wrote: > > > >> On Wednesday, 24 June 2020 at 20:34:24 -0700, Donald Wilde wrote: > >> > On 6/24/20, Greg 'groggy' Lehey <grog@freebsd.org> wrote: > >> >> On Wednesday, 24 June 2020 at 18:51:04 -0700, Donald Wilde wrote: > >> >>> On 6/24/20, Greg 'groggy' Lehey <grog@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@gmail.com PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683
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