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View Full Version : Cloning to defragment and Time Machine


D60Dave
03-03-2010, 10:27 AM
Hi All,

I bought an extra SATA drives for my MacPro and last night I set about cloning my system disk to this new disk to produce a defragmented clone using SuperDuper as described here: http://homepage.mac.com/dnanian/SuperDuper/Fragmentation.pdf

According to iDefrag my original system disk had over 4000 fragmented files (demo version will tell you this) and the cloned disk had just over 100. A great improvement! (I now realise I should have created the clone after booting in safe mode, I wonder if this will reduce the figure below 100??)

Anyway, I was quite pleased with that but when I came to turn Time Machine back on (which I updated just before doing the clone) it started doing a full back up of my cloned system disk, about 86GB. Should this cloned disk not appear identical to Time Machine as the original disk? Could it be because I've named the volume differently ie original sys disk = 'Mac HD', cloned sys disk = 'Sys DiskB' ?? Does anyone know how to overcome this and get TimeMachine to see it as the same drive? Is it as simple as calling them both the same, that could get confusing though???

Regards,
Dave.

dnanian
03-03-2010, 10:29 AM
If you erased the drive, it's going to look different (and certainly renaming it would make it different, too), Dave...

D60Dave
03-03-2010, 11:06 AM
- Thanks for your reply.

I haven't erased either drive. I'm talking about the new clone, if I name this "Mac HD" (the same name as the drive it's a clone of) should Time Machine think it's the same drive and only back up changes rather than the whole thing from scratch?

I'll try it tonight when I get home.

Regards,
Dave.

dnanian
03-03-2010, 11:09 AM
Not necessarily, no. It's hard to know for sure what TM uses to identify drives, although it's likely using a cookie on the drive that we preserve, unless you erase the drive.

D60Dave
03-03-2010, 11:18 AM
- thanks for your prompt reply, I'll check it out tonight and let you know what happens.

Cheers,
Dave.