On Wed, Aug 10, 2011 at 08:27:27AM +0000, Holger Kipp wrote: > > Am 10.08.2011 um 10:09 schrieb Daniel Kalchev: > > > On 10.08.11 10:47, Jeremy Chadwick wrote: > >> On Wed, Aug 10, 2011 at 10:13:14AM +0300, Daniel Kalchev wrote: > >>> I am more concerned that with 32GB of swap in single device I could not > >>> dump kernel core, with 64GB of RAM. > >> My apologies if I've misunderstood something, but why does this of any > >> concern? Machine has 64GB RAM. You have a single swap slice that's > >> effectively 32GB. How is a kernel panic worth of 64GB RAM going to fit > >> into a 32GB swap slice? > >> > > The swap partitions are 64GB, it is only that FreeBSD refuses to use more > > than 32GB of each for swap. But.. it might happily dump core to the whole > > partition, tests will show. > > I doubt it. Have you tried increasing kern.maxswzone? It is the size in KB > (for 32GB it is set to 33554432). > kern.maxswzone: Maximum memory for swap metadata
The variable is set to 32MBytes, not 32GBytes. The default size is defined as variable VM_SWZONE_SIZE_MAX, which is 32*1024*1024 per sys/i386/include/param.h and sys/amd64/include/param.h. Furthermore, this variable does not do what you're implying. It's used within swap_pager_swap_init() in sys/vm/swap_pager.c, which is what's used for initialising a process that's being paged out (swapped out). That doesn't appear to have anything to do with actual memory dumps. So we're back to where we started: swap slices/partitions can be greater than 32GBytes in size, but "something" is limiting the maximum amount of memory which can be dumped to a single swap swap to 32GBytes. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, US | | Making life hard for others since 1977. PGP 4BD6C0CB | _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
