ZFS trouble: unbelievably large files created

[David Samms]

I am running into issues with ZFS where perl, specifically amavisd 
running spamassassin creates unbelievably large files, as in files 100x 
the size of the hard disk.

My setup is a host run a dozen jails.  The host is amd64 FreeBSD 
8.1-RELEASE-p1 #6 as of Thu Sep 30.  The jails are running 8.0 release 
as I have not yet upgraded them.  This setup has been very stable till I 
introduced ZFS.  Below is the zpool setup:

zpool status
   pool: m1012
  state: ONLINE
  scrub: none requested
config:

         NAME        STATE     READ WRITE CKSUM
         m1012       ONLINE       0     0     0
           mirror    ONLINE       0     0     0
             ad10    ONLINE       0     0     0
             ad12    ONLINE       0     0     0

Last night I moved six jails from my UFS+S RAID5 file system to the new 
ZFS file system.  Since then perl occasionally runs at 100% disk usage 
accessing files in /var/amavis/.spamassassin  Here is the current 
directory listing:

ls -l .spamassassin
total 13352131
-rw-------  1 vscan  vscan           684032 Oct 15 12:02 auto-whitelist
-rw-------  1 vscan  vscan               40 Oct 15 12:37 bayes.lock
-rw-------  1 vscan  vscan          1294336 Oct 15 12:38 bayes_seen
-rw-------  1 vscan  vscan          4227072 Oct 15 12:38 bayes_toks
-rw-------  1 vscan  vscan     553184002048 Oct 15 12:38 
bayes_toks.expire3515
-rw-------  1 vscan  vscan  140743122878464 Oct 15 12:14 
bayes_toks.expire97254

The last file is 140TB which is pretty good sized for a 1TB disk.  Disk 
compression is OFF.  du -hs reports 13G int the .spamassassin directory.

Any thoughts?