I tried this under the 'drives/storage' category but didn't get any response. Maybe I'll have better luck here.
Anyway, I've got two 73G raptors in Raid0 on my machine (running XP SP3).
Its been awhile so I went to defrag the drive, did the analyze, and sure enough it needed it - have
11% total fragmentation, 22% file fragmentation.
But when I go to actual do the defrag, it starts up, runs for a few minutes and kicks out - along with a note that some files could not be defrag'd. When I look at the report, the fragmentation %'s haven't changed - but it does not list any files that couldn't be defrag'd. Weird.
Anybody ever seen this and have any clues as to how to correct it??
I don't know why it does not list the undefragmentable files, but to the best of my knowledge, you get incomplete defragmentation with the 'some files could not be defragged' message in the following situations:
(a) System files (MFT, page files) are fragmented.
(b) Insufficient free disk space to defrag the files.
For (b) you can try to clear up some disk space via disk cleanup.
For (a) you'll need to get a third party tool that can defrag the system files. I don't have a RAID setup* but I use diskeeper 2008 pro for my system and it's excellent. Defrags quickly and is pretty customizable with different defrag modes. You can download free trialware from their website if interested.
* It does not matter if it's a single drive or RAID0 since the distinction is not made at the file system level but at the drive hardware controller level. As far as windows is concerned, even a RAID0 is a single logical drive.