FreeBSD 8.1-Prerelease Panic amd64 w/ZFS..

[Darren Pilgrim]

Jeremy Chadwick wrote:
> To the OP: you will need to increase vm.kmem_size in /boot/loader.conf
> and reboot the system.  "What value do I pick?"  With 4GB, I would
> recommend you use these two variables:
> 
> vm.kmem_size="2048M"
> vfs.zfs.arc_max="1536M"
> 
> This will increase the available kmem, and also limit the ARC size
> explicitly to nothing larger than 1.5GB.  This should stabilise your
> system.

What are the general guidelines for sizing these given the amount of 
physical RAM?  For example, I have a machine with 6 GB, so I have:

vm.kmem_size="3072M"
vfs.zfs.arc_max="2048M"