On 6/25/20, Paul Mather <paul at gromit.dlib.vt.edu> wrote:> On Jun 24, 2020, at 11:34 PM, Donald Wilde <dwilde1 at gmail.com> wrote: > > > I think I've missed in this thread where you said which FreeBSD arch you are > running: is it FreeBSD/amd64 or FreeBSD/i386? (With an "old" machine, 4 GB > RAM, and an install still using MBR, it could potentially be FreeBSD/i386.) >Sorry, Paul. You're right, I didn't say. amd64. Here's 'uname -a' FreeBSD Synergy000010 12.1-STABLE FreeBSD 12.1-STABLE r362500 LIBERTYSERVER amd64> If it is FreeBSD/i386, there is a precedent for it having problems with > configuring large amounts of swap. However, it is usually related to having > relatively little RAM, too (large amounts of swap space means the OS needs > to use more RAM to keep track of it). >That's good to know, Paul. I am once again doing embedded work, which means I will be coding 32-bit ARM M7's soon enough. Here's 'pstat -s' on the i3 (which registers as cpu HAMMER): Device 1K-blocks Used Avail Capacity /dev/ada0s1b 33554432 0 33554432 0% /dev/ada0s1d 33554432 0 33554432 0% Total 67108864 0 67108864 0% -- Don Wilde **************************************************** * What is the Internet of Things but a system * * of systems including humans? * ****************************************************
26.06.2020 1:30, Donald Wilde wrote:> Here's 'pstat -s' on the i3 (which registers as cpu HAMMER): > > Device 1K-blocks Used Avail Capacity > /dev/ada0s1b 33554432 0 33554432 0% > /dev/ada0s1d 33554432 0 33554432 0% > Total 67108864 0 67108864 0%"pstat -s" may also be invoked as "swapinfo" or better "swapinfo -h".
On 2020-Jun-25 11:30:31 -0700, Donald Wilde <dwilde1 at gmail.com> wrote:>Here's 'pstat -s' on the i3 (which registers as cpu HAMMER): > >Device 1K-blocks Used Avail Capacity >/dev/ada0s1b 33554432 0 33554432 0% >/dev/ada0s1d 33554432 0 33554432 0% >Total 67108864 0 67108864 0%I strongly suggest you don't have more than one swap device on spinning rust - the VM system will stripe I/O across the available devices and that will give particularly poor results when it has to seek between the partitions. Also, you can't actually use 64GB swap with 4GB RAM. If you look back through your boot messages, I expect you'll find messages like: warning: total configured swap (524288 pages) exceeds maximum recommended amount (498848 pages). warning: increase kern.maxswzone or reduce amount of swap. or maybe: WARNING: reducing swap size to maximum of xxxxMB per unit The absolute limit on swap space is vm.swap_maxpages pages but the realistic limit is about half that. By default the realistic limit is about 4?RAM (on 64-bit architectures), but this can be adjusted via kern.maxswzone (which defines the #bytes of RAM to allocate to swzone structures - the actual space allocated is vm.swzone). As a further piece of arcana, vm.pageout_oom_seq is a count that controls the number of passes before the pageout daemon gives up and starts killing processes when it can't free up enough RAM. "out of swap space" messages generally mean that this number is too low, rather than there being a shortage of swap - particularly if your swap device is rather slow. -- Peter Jeremy -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 963 bytes Desc: not available URL: <http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20200626/5ecc6581/attachment.sig>