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

[Doug Poland]

On Fri, January 22, 2010 07:22, Doug Poland wrote:
> On Fri, January 22, 2010 00:09, Artem Belevich wrote:
>> 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!
>>>
>> 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"
>>
> OK, I'll give that a shot...
>

panic: kmem_malloc(131072): kmem_map too small: 3593236480 total
allocate d

# cat /boot/loader.conf
vfs.root.mountfrom="zfs:bethesda"
vfs.zfs.arc_max="1G"
vm.kmem_size="20G"
zfs_load="YES"

OK, what do we do next? :)


-- 
Regards,
Doug