Time Machine & bootable backup on same drive

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Switched out my original 160GB HD for a 500GB HD. The 160GB HD becomes an external. Right now I only used about 26-27GB total. Pretty sure I should be able to designate my 160GB external as a backup drive under Time Machine and also retained it as bootable. Using Time Machine, it won't wipeout the drive will it? It should just write the 26ish GB and keep the backup folder/files into the 160GB external drive right...
 

bobtomay

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You cannot use the same partition for a cloned bootable backup and store TM backups.

While you can write to and store other data on a TM backup partition, both SD! and CCC create exact duplicates of your internal drive... meaning, anything that is not on your internal drive is deleted from it.

To maintain both a bootable backup and a TM backup, at a minimum you will have to create two partitions on a single drive... however, with only a 160GB drive, I'd recommend using only one or the other... my personal first choice is a bootable backup before a TM backup.
 
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quin
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Thanks 'bob'

So just to confirm my understanding; to back up with Time Machine on my bootable, external 160GB original HDD, I would have to either partitioned or designate as a backup drive through Time Machine and essentially wiping out original data. Correct?
 

bobtomay

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Having a bootable external drive is not the same as having a bootable backup external drive.

If you have just removed your original drive and slapped it into an external enclosure and are now able to boot from that drive without using SD! or CCC and wish to add a TM backup to that partition - should be able to do that - although I would not recommend it.

Yes, in order to use TM, you have to tell it what drive/partition, you want it to use. TM does not delete any other data on the drive/partition and has the ability to co-exist with other data but it is not a bootable backup.

If you are going to use SD! or CCC to create and maintain a bootable "backup", each of those apps create an identical clone of your internal drive - adding what is missing on the external and deleting what is not on the internal drive. Both of these will delete any TM backup or any other data you have added that does not exist on your internal drive. This is my personal first choice for a backup. Yes, in this scenario, you will need to partition the drive and use one partition for the bootable backup and the other for TM.
 
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quin
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Having a bootable external drive is not the same as having a bootable backup external drive.

If you have just removed your original drive and slapped it into an external enclosure and are now able to boot from that drive without using SD! or CCC and wish to add a TM backup to that partition - should be able to do that - although I would not recommend it.

I apologized for my misleading wording :Oops: I only keep the original 160hd(external) as a 'backup' in case I need to put it back into the MBP for repair purpose with Apple or somehow my internal 500gb craps out. At the same time, I would like to have it designate and store TimeMachine backup in it. Instead of having it sitting in an enclosure doing nothing, since I'm only taking up 26GB so far. Thanks.
 

bobtomay

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No problem. Just wanted to make sure we were both on the same page and clear for future readers.
 

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