ZFS deadlock

[Johan Ström]

Hello

A box of mine running RELENG_7_0 and ZFS over a couple of disks (6  
disks, 3 mirrors) seems to have gotten stuck. From Ctrl-T:

load: 0.50  cmd: zsh 40188 [zfs:&buf_hash_table.ht_locks[i].ht_lock]  
0.02u 0.04s 0% 3404k
load: 0.43  cmd: zsh 40188 [zfs:&buf_hash_table.ht_locks[i].ht_lock]  
0.02u 0.04s 0% 3404k
load: 0.10  cmd: zsh 40188 [zfs:&buf_hash_table.ht_locks[i].ht_lock]  
0.02u 0.04s 0% 3404k
load: 0.10  cmd: zsh 40188 [zfs:&buf_hash_table.ht_locks[i].ht_lock]  
0.02u 0.04s 0% 3404k
load: 0.11  cmd: zsh 40188 [zfs:&buf_hash_table.ht_locks[i].ht_lock]  
0.02u 0.04s 0% 3404k

Worked for a while then that stopped working too (was over ssh). When  
trying a local login i only got

load: 0.09  cmd: login 1611 [zfs] 0.00u 0.00s 0% 208k

I found one post like this earlier (by Xin LI), but nobody seemed to  
have replied...
in my current conf, I think my kmem/kmem_max is at 512Mb (not sure  
though, since I've edited my file yesterday for next reboot), with 2G  
of system RAM.. Normally I'd run kmem(max) 1G (with arcsize of 512M.  
currently it is at default), but since I just got back to 2G total mem  
after some hardware problems I've been runnig at those lows (1G total  
is kindof tight with zfs..)

Well, just wanted to report... The box is not totally dead yet, ie I  
can still do Ctrl-T on console, but thats it.. I don't really know  
what more I can do so.. I don't have KDB/DDB.
I'll wait another hour or so before I hard reboot it, unless it  
"unlocks" or if anyone have any suggestions.

Thanks

--
Johan Ström
Stromnet
johan at stromnet.se
http://www.stromnet.se/