Drive Genius 2

nagol · **Joined:** Mon Aug 17, 2009 1:58 am **Posts:** 2

trying to defrag G5 disks are mirrored with red ! marks run it on the main drive not the splits starts fine then says there is an error repair disk tried to use DG and apple utilities but repair option not a selectable option greyed out So can it defragment a mirrored drive?? Thanks in advance

Michael Snow · **Posted:** Mon Aug 17, 2009 4:25 am

Their web site says that they do not support RAID drives.

Do you know that OS X defragments files on the fly as they are accessed?

nagol · **Joined:** Mon Aug 17, 2009 1:58 am **Posts:** 2

thanks for that :-(

re defrag on the fly thought it was only files upto 20mb?
we deal in image files far larger than that drive genius gives a snap shot of the drives and they look like they have been hit with a shot gun

Michael Snow · **Posted:** Mon Aug 17, 2009 6:43 pm

You're right about the 20 MB limit.

Amit Singh says

Quote:

When a file is opened on an HFS+ volume, the following conditions are tested:

* If the file is less than 20 MB in size
* If the file is not already busy
* If the file is not read-only
* If the file has more than eight extents
* If the system has been up for at least three minutes

If all of the above conditions are satisfied, the file is relocated -- it is defragmented on-the-fly.

As understand, you can achieve the same defragmenting effect by moving the 20+ MB file to another drive, then back to the working system. Relocating the file defragments it.