RAID-0 defrag / array failure

MURDEROUS G · 22 Dec 2008 at 05:09

OK, so, I've had this RAID-0 setup for a good few months now, figure it's about time to defrag it. Probably long past time, in truth. I don't know much about handling RAID fragmentation so I google around, and read a few threads from this forum, and everything I can find says that defragging a RAID-0 array is just like defragging any other drive and should help performance. So off I go with my app of choice (defraggler).

After about two or three minutes of defragging the drive, a very worrying icon appears in the systray.

What?? Everything I read said that defragging definitely should not endanger the integrity of the array. Is this some kind of false positive caused by the defrag or should I legitimately be crying into my festive pint, like I currently am? Any advice?

GeezerButler · 22 Dec 2008 at 09:59

Are your RAID controller drivers up to date? I used to see problems on Dell PCs with Intel RAID controllers and Samsung HDDs where the controller would flag a drive as faulty when it isn't - later drivers from Intel fixed the problem.

Mike1983 · 22 Dec 2008 at 14:20

I've got a RAID 0 array and defrag very frequently but I've never had this problem. I use O&O defrag but as you point out I've not come across anything suggesting that defragging a RAID array is different to any other HDD so the choice of program should just be down to personal preference rather than one specifically aimed at RAID.

Maybe it was just a coincidence this happened during defragging and you could have gotten this problem if you were to have just done a standard file transfer or something.

GrantJ · 22 Dec 2008 at 16:48

I don't use RAID 0, but some of my friends do on XP Pro setups, and a couple use Diskeeper for defrag. Works perfectly fine without any issues.

You are right, any decent defragger should be able to see the array as a single logical drive, not two disks, because that differentiation is made at the controller level. Windows and any defragger that runs within it, treats RAID 0 just as it would a single logical disk.

Stonedofmoo · 22 Dec 2008 at 17:15

It could just be defragging has moved data to an area of a drive thats faulty which has thrown up the error. Defragging itself won't cause a drive failure any more so than normal daily use.

Nothing to be done but backup data and then run a scan of each hard disk using the manufacturers utility.

oddjob62 · 23 Dec 2008 at 20:51

Stonedofmoo said:
It could just be defragging has moved data to an area of a drive thats faulty which has thrown up the error. Defragging itself won't cause a drive failure any more so than normal daily use.

Nothing to be done but backup data and then run a scan of each hard disk using the manufacturers utility.

Most likely. A Defrag shouldn't do any harm to a "healthy" set of disks in RAID 0