Shadow backup hangs

[HeyCompMan]

Basic problem: am using shadow copy to backup our Proliant ML310 G5 domain controller system and data partitions. Source is E200 RAID 0+1 twin 250gb's onto a target third drive in the E200 array, set as RAID 0. Recently it hung in the middle of a backup saying there was a problem on the target drive and that data was lost. This has worked for several months on this setup. I checked the drive. It turned out to be heavily fragmented according to the defrag utility. I ran the defrag once and there still was a fair amount of fragmented content. So I ran it again. Now there is a fairly sizable red fragmented area on the high (right) end of the defrag analysis. Not sure why defrag doesn't clear the problem. Also not sure why shadow copy produces so much fragmentation. What should I do??

Thank you, David Johnston