panic after starting jail

[Iain Dooley]

hi there,

> uname -a
FreeBSD socata.scoastnet.com.au 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Sun 
May  7 04:42:56 UTC 2006 
root at opus.cse.buffalo.edu:/usr/obj/usr/src/sys/SMP  i386

i'm running three jails on the above server. this morning one of them 
appears to have begun doing something diabolical to the filesystem. when i 
try to start it, i get something like:

start = 0 len = 2
panic: ffs_alloccg: map corrupted
cpuid = 0
Automatic reboot in 15 seconds

i then have to boot into single user mode and run fsck, then take 
jail_enable out of rc.conf in order to boot up.

the other two jails are fine.

i've taken a look at /var/log/messages on the host machine as well as on 
the affected jail and i can't see anything out of the ordinary.

does anyone have any clues as to how i could find out what went wrong?

sincerely,

iain dooley