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

[Doug Poland]

Hello,

I've got an 8.0-STABLE (amd64) box with 4GB RAM.  The machine is running 
off a 6-disk RAIDZ1 booting from GPT.  The box consistently panics on 
unixbench's fsdisk program.

I have been gathering some metrics in an attempt to isolate the 
parameters that are significant, but I admit I do not really understand 
all the relationships.  At this point, I have nothing set in 
/boot/loader.conf

Here are some of the values I was recording within seconds of the panic:

# dmesg | grep memory
real memory  = 4294967296 (4096 MB)
avail memory = 3961372672 (3777 MB)

kstat.zfs.misc.arcstats.size: 308522248
vfs.zfs.arc_max: 829480960
vfs.zfs.arc_meta_limit: 207370240
vfs.zfs.arc_meta_used: 165575944
vfs.zfs.arc_min: 103685120
vm.kmem_size: 1327169536
vm.kmem_size_max: 329853485875

# vmstat -m | egrep 'InUse|solaris'
          Type InUse MemUse HighUse
       solaris 491349 1316172K       -

% zpool status
   pool: bethesda
  state: ONLINE
  scrub: none requested
config:

         NAME           STATE     READ WRITE CKSUM
         bethesda       ONLINE       0     0     0
           raidz1       ONLINE       0     0     0
             gpt/disk0  ONLINE       0     0     0
             gpt/disk1  ONLINE       0     0     0
             gpt/disk2  ONLINE       0     0     0
             gpt/disk3  ONLINE       0     0     0
             gpt/disk4  ONLINE       0     0     0
             gpt/disk5  ONLINE       0     0     0

errors: No known data errors

My concern is if I can panic the box with a simple file system 
benchmark, what will happen when I rysnc files across a 1GB LAN 
connection?   I am very willing to run any number of tests and tweek ZFS 
as necessary.  Please advise.


-- 
Regards,
Doug