Backing up an External HDD to Time Machine

[nuck]

Question.. I have set up an external hard drive ("Hard Drive A") to backup to my Time Machine external hard drive ("Hard Drive B"), but I cannot figure out how to view the backups unless that external hard drive (A) is plugged in.

For example:

If Hard drive A is plugged in, and I go to "Enter Time Machine" I can see Hard drive A listed under devices in the backup and see the files.

If Hard drive A is NOT plugged in and I "Enter Time Machine" I can't see Hard drive A listed and can't access the files.

Does anyone know how to view these files? If I need Hard Drive A to be working and plugged in to access it then the whole backup is worthless since the whole point is to back things up to Hard Drive B (Time Machine) in case hard drive A stops working.

Thanks

 

[komatsu]

I might be wrong about this but I think Time Machine is primarily designed to backup your Mac's internal HDD but I'm sure some other people will have some other input on this.

 

[MC6800]

If A dies you could theoretically replace it with a new drive and restore its Time Machine contents from B. But normally you wouldn't do it that way: for redundancy you would have both A and B backing up the same Mac drive(s).

In any event, the contents of an unencrypted Time Machine backup is a set of folders, one per backup event, that are just as readable as the original drive. They use hard links to make one actual file appear in multiple folders without taking extra space if it didn't change.

 

[chabig]

I would discourage you from backing up your Time Machine drive. Instead, just add the second drive to your Time Machine settings and the Mac will alternately use both drives. That way you have two independent backups. You can even rotate them--store one offsite and swap them out every week/two weeks/four weeks, whatever is convenient for you.

 

[Fishrrman]

Instead of creating a second TM backup, I suggest that you download either CarbonCopyCloner or SuperDuper (both are FREE to download and try for 30 days).

Then, create a bootable cloned backup on your second external drive.

Now you'll have both a TM backup AND a bootable cloned backup.

Give either CCC or SD a try.
If you don't care for them, you can always just erase the external backup and start over.

 

[chabig]

Instead of creating a second TM backup, I suggest that you download either CarbonCopyCloner or SuperDuper (both are FREE to download and try for 30 days).

Then, create a bootable cloned backup on your second external drive.

Now you'll have both a TM backup AND a bootable cloned backup.

Give either CCC or SD a try.
If you don't care for them, you can always just erase the external backup and start over.

That is also an excellent idea.

 

[nuck]

If A dies you could theoretically replace it with a new drive and restore its Time Machine contents from B. But normally you wouldn't do it that way: for redundancy you would have both A and B backing up the same Mac drive(s).

In any event, the contents of an unencrypted Time Machine backup is a set of folders, one per backup event, that are just as readable as the original drive. They use hard links to make one actual file appear in multiple folders without taking extra space if it didn't change.

This is fantastic. Thanks everyone!