>> * vm.kmem_size >> * vm.kmem_size_max > > I tried kmem_size_max on -current (this year), and I got a panic during use, > I changed kmem_size to the same value I have for _max and it didn't panic > anymore. It looks (from mails on the lists) that _max is supposed to give a > max value for auto-enhancement, but at least it was not working with ZFS > last month (and I doubt it works now).
It used to be that vm.kmem_size_max needed to be bumped to allow for larger vm.kmem_size. It's no longer needed on amd64. Not sure about i386. vm.kmem_size still needs tuning, though. While vm.kmem_size_max is no longer a limit, there are other checks in place that result in default vm.kmem_size being a bit on the conservative side for ZFS. >> Then, when it comes to debugging problems as a result of tuning >> improperly (or entire lack of), the following counters (not tunables) >> are thrown into the mix as "things people should look at": >> >> kstat.zfs.misc.arcstats.c >> kstat.zfs.misc.arcstats.c_min >> kstat.zfs.misc.arcstats.c_max > > c_max is vfs.zfs.arc_max, c_min is vfs.zfs.arc_min. > >> kstat.zfs.misc.arcstats.evict_skip >> kstat.zfs.misc.arcstats.memory_throttle_count >> kstat.zfs.misc.arcstats.size > > I'm not very sure about size and c... both represent some kind of current > size, but they are not the same. arcstats.c -- adaptive ARC target size. I.e. that's what ZFS thinks it can grow ARC to. It's dynamically adjusted based on when/how ZFS is back-pressured for memory. arcstats.size -- current ARC size arcstats.p -- portion of arcstats.c that's used by "Most Recently Used" items. What's left of arcstats.c is used by "Most Frequently Used" items. --Artem _______________________________________________ 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"
