zfs, 1 gig of RAM and periodic weekly

[Eugene M. Zheganin]

Hi.

I'm haunted by a weird bug.
Some of my servers (IBM x3250) hang periodically. And this is always 
saturday morning. Different servers in different cities, all with zfs 
and one gig of RAM. And yeah, it's periodic weekly. I can say more - 
it's  repeatable. 25 minutes ago I typed 'periodic weekly', and 5 
minutes ago I lost this machine from the network (even stopped answering 
to ICMP). This can be solved by any of two methods - either increase 
RAM, or turning off periodic weekly.

loader.conf (doesn't help):

zfs_load="YES"
vfs.root.mountfrom="zfs:zfsroot"
ng_iface_load="YES"
ng_ether_load="YES"
vm.kmem_size="330M"
vm.kmem_size_max="330M"
vfs.zfs.arc_max="30M"

This is 8.2-RELEASE/amd64.

The most important question - what to report and how to report this ?

Thanks.
Eugene.