DSM-G600, DNS-3xx and NSA-220 Hack Forum

I recently upgraded my DNS-323 to firmware 1.06, and put in two new 1TB Samsung disks (JBOD).  It seemed to work like a dream for a few days, but then the past few days I have walked into the room with the unit only to find that the disk heads are making a lot of noise, like they're writing a ton of data all over the disks (sounds like the drive heads are seeking as fast as they can, nonstop), even though all of the computers on the network are off.  The strange thing is it doesn't seem to interfere with the unit's functioning - I haven't had any problems reading or writing to the NAS.

I'm using fonz's fun_plug (ffp 0.5) and am running Mediatomb 0.11.0-6 and firefly.  I do have a good amount of music on one of the disks, but I tried to set Mediatomb to rescan only once a day, and firefly I haven't done anything with.  At any rate, even when I shut down Mediatomb, I still get the excessive disk activity.

Can anyone here help me figure out what is causing the constant disk activity?  I have tried to clear the print queue, so I don't think that's the problem.  I don't know much Linux, so I don't know how to diagnose the problem myself.  When I issue the 'ps' command in a telnet session, I get the following (most options don't seem to work with the built-in 'ps' command, so I'm not sure how to get more information or to find out what resources the processes are using):

PID   USER     COMMAND
    1 root     init
    2 root     [ksoftirqd/0]
    3 root     [events/0]
    4 root     [khelper]
    5 root     [kthread]
   11 root     [kblockd/0]
   14 root     [khubd]
   49 root     [pdflush]
   50 root     [pdflush]
   52 root     [aio/0]
   51 root     [kswapd0]
  190 root     [scsi_eh_0]
  191 root     [scsi_eh_1]
  192 root     [scsi_eh_2]
  193 root     [scsi_eh_3]
  204 root     [mtdblockd]
  218 root     [kcryptd/0]
  219 root     [kmirrord/0]
  230 root     [loop0]
 1213 root     atd
 1581 root     chkbutton
 1606 root     /web/webs
 1610 root     fancontrol
 1629 root     crond
 1646 root     /usr/sbin/samba/smbd -D
 1650 root     /usr/sbin/samba/nmbd -D
 1654 root     /usr/sbin/samba/smbd -D
 1656 root     op_server 3 3 3
 1663 root     -sh
 1710 root     lpd Waiting
 1812 root     /ffp/sbin/sshd
 1860 root     /ffp/sbin/lighttpd -f /ffp/etc/lighttpd.conf
 2090 root     sshd: root@pts/0
 2096 root     -bash

The only entries in the cron table are two 'rtc' entries.  Not sure what they are, though I seem to recall seeing a post saying they have something to do with internal clock adjustments.

Any help would be appreciated.  Suggestions for diagnostic tests, etc.  I'm afraid I'm going to lose my drives pretty soon if I can't get this fixed!  Thanks in advance!