[COLUG] Linux RAID problem

[Dane Miller]

Hi all,

I'm hoping someone might have some ideas about a frustrating server
problem I am experiencing.  My log files are recording nothing out of
the ordinary and I can predictably crash my server... ouch :(

Recently, whenever I do a full backup of /home on the server, about
fifteen minutes into the backup the server completely locks up. No ping
response, no console access, unable to wake monitor from power saving
mode.  So I do a hard power-off. 

/home lives on a software RAID 1 array of 3 80gb Western Digital ATA100
disks (2 active disks + 1 spare).  When I reboot the box the RAID 1
mirror has to be rebuilt.  The specific error message in dmesg is "md:
md0: raid array is not clean -- starting background reconstruction" 

I am performing the backup with ssh, tar, and gzip over the network.

This problem started earlier this month and after repeated crashes,
caused hardware failure in the two active 80gb disks.  Since then, I've
replaced the power supply and the two active disks.

The server is a Libranet 2.8.1 Debian Sarge/Unstable box.  Kernel
2.4.20.  raidtools-1.00.3

Any thoughts?  Hardware? Software?  

Any suggestions would be really appreciated.

Thanks,
Dane