Repeatable ZFS "kmem map too small" panic on 8.0-STABLE

[Artem Belevich]

Next step would be to set vfs.zfs.arc_max to a value that's somewhat
below your physical memory size. Let's say - 1G or so. On my box with
8GB of RAM I set these values:

vfs.zfs.arc_max="6500M"
vfs.zfs.arc_min="4G"

You didn't mention how recent is your kernel. There were quite a few
bugfixes committed to -8. Make sure your kernel is r201987 or newer.

--Artem



On Thu, Jan 21, 2010 at 8:28 PM, Doug Poland <doug at polands.org> wrote:
> Interesting discussion :)  I added vm.kmem_size="20G" to
> /boot/loader.conf per your instructions.  This time, it didn't panic at
> the same point in the test, however, it appears the filesystem is
> "hanging".
>
> On the fdisk test, I hit <CTRL> T and get:
> cmd: fsdisk 37066 [zio->io_cv)] 245.62r 0.12u 25.10s 0
>
> My various metrics are still running, but anything that needs the
> filesystem appears "stuck".
>
> The memory usage of the item "solaris" (vmstat -m | grep solaris) spiked
> at 3334781952 (3180.30 MiB).
>
> # zpool iostat 2, a <CTRL> T shows:
> load: 0.00  cmd: zpool 934 [tx->tx_quiesce_done_cv)] 2052.45r 0.06 u 0.39s 0% 0k
>
> # vmstat -v | grep solaris to disk every second and it's
> hung at:
> load: 0.00  cmd: sh 38551 [zfs] 909.85r 0.00u 0.00s 0% 16k
>
> Any suggestions!
>
> --
> Regards,
> Doug
>