Plug Locks up after a few days

[bradles]

I have a plug computer running debian squeeze. It is mainly running to serve a couple of NFS shares to my WDTV box. Over the past 2 weeks I have had 2 instances where the box has locked up to the point where it was completely unresponsive from the network. Both times a reboot (unplug/replug) works without issues. There is nothing I can seen in the log files that indicate anything that failed. The most recent time it happened while I was watching a video and the log file seems to stop a while before the lock up and then restarts during the reboot. The plug is in a closet so I was unable to connect to console during this time. The root file system is on the SD card rather than the internal NAND. Could there be some problem writing to the SD card that causes a downward spiral ? Snippet from syslog is bellow. Any recommendations ? I was thinking about perhaps moving /var/log to the USB attached disk to see if that catches anything . . . Any help or direction would be appreciated.

Syslog:
Apr 14 20:45:01 debian /USR/SBIN/CRON[24594]: (root) CMD (/opt/scripts/ethernet.sh update)
Apr 14 20:45:01 debian /USR/SBIN/CRON[24601]: (root) CMD (/opt/scripts/load.sh update)
Apr 14 20:45:01 debian /USR/SBIN/CRON[24602]: (root) CMD (/opt/scripts/memory.sh update)
Apr 14 16:30:21 debian kernel: imklog 4.4.2, log source = /proc/kmsg started.
Apr 14 16:30:21 debian kernel: Linux version 2.6.30.2 (kelly@speedy) (gcc version 4.2.1) #11 PREEMPT Wed Jul 22 19:53:31 MDT 2009
Apr 14 16:30:21 debian kernel: CPU: Feroceon 88FR131 [56251311] revision 1 (ARMv5TE), cr=00053977
Apr 14 16:30:21 debian kernel: CPU: VIVT data cache, VIVT instruction cache
Apr 14 16:30:21 debian kernel: Machine: Marvell SheevaPlug Reference Board
Apr 14 16:30:21 debian kernel: Memory policy: ECC disabled, Data cache writeback
Apr 14 16:30:21 debian kernel: On node 0 totalpages: 131072

[Trune]

its not a rather hot closet is it?

[bradles]

No not at all. the house has been in the mid 60's the last couple of days and the closet door has been open. Interestingly I could ping the device but ssh and http stopped responding.

I think I'll move /var/log to the USB disk tonight to see if there is any more data available when it happens next time

[pingtoo]

Is you USB disk activity light on constantly when your plug not responsive? I have some problem when I connect more then one USB disk to a PC, linux usb storage seems have problem when heavy I/O happen.