Hello, I'd like to add another instance of similar problems. I recently updated my FreeBSD amd64 box with ZFS root and 8GB RAM from 8-STABLE (as of Mar 1st) to 8.1-PRERELEASE (as of May 27th). After that, my box started to crash every couple of days due to kmem_map too small.
Here is a (last week) screenshot of Munin graph about the memory usage of the box: http://eron.info/munin-memory.png In "by month" graph, a white gap at the end of "Week 20" is the update period from 8-STABLE to 8.1-PRERELEASE I mentioned above. Before the upgrade, the system was rock solid without any kmem tuning in loader.conf (vm.kmem_size was around 2.7GB IIRC). After the update, I could see that more wired memory was assigned, and then steep drop (crash) occured. "by day" graph shows my experiment to bump vm.kmem_size=12G (recommended somewhere in this thread) and explicitly limit vfs.zfs.arc_max=2G. I was surprised because the wired memory quickly increased over 5GB... Then I noticed that the default value of vfs.zfs.zio.use_uma was 1 on amd64, so I turned it off and removed other memory tunings (kmem_size and arc_max) in loader.conf on Tuesday at 16:00 and rebooted. It seems that the usage of wired memory was stablized and no crash since then with the default kmem_size and arc_max. Does anyone have any idea about this behavior? My wild guess is that ZFS/UMA code is not stable on amd64 too, and it should be turned off by default for 8.1-RELEASE maybe.... Regards, -- Yoshiaki Kasahara Research Institute for Information Technology, Kyushu University kasah...@nc.kyushu-u.ac.jp _______________________________________________ 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"
