Can I use Time Machine on a second external HD?

Question

Can I use Time Machine on a second external HD?

I just bought a new Mac Studio and purchased a 2TB SSD external drive for my client files.

I also purchased an 8TB drive (traditional, not SSD) as my Time Machine backup.

PROBLEM: While I can select my Mac Studio on Time Machine, the 2TB client external is grayed-out and I cannot select it on Time Machine.

Is there a solution for this? The client files are what I really need Time Machine to archive and backup.

FYI, my Mac Studio does not have enough storage to hold all my client files because the back order for a larger storage Mac Studio was impractically all the way until July.

Thanks in advance.

Posted on Apr 10, 2022 7:58 PM

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Answer 1

Top-ranking reply

Tesserax

Level 10

152,320 points

Apr 11, 2022 9:12 AM in response to Scarab and Bone

I was the one that made that comment. In order for TM to back up to this APFS-formatted drive, the drive's volume used by TM, will be "dedicated" to TM.

If your goal is to use this drive for other purposes, in addition to TM, you have two choices:

Partition the drive to have multiple containers. What was called partitions in HFS+, are know called containers. Containers, on the other hand, can have multiple volumes. As a minimum have two containers. TM will properly format the container with a volume dedicated to its use. The other container can then be used for files.
Keep a single container on the drive. Instead of creating another one, create as many additional volumes within the single container as needed.

Ref: Juggling with HFS+ and APFS partitions and volumes: a primer - The Eclectic Light Company

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Answer 2

markwmsn

Level 6

15,635 points

Apr 10, 2022 9:28 PM in response to Scarab and Bone

Where are you doing this selection? Normally, you would select the 8TB in System Preferences > Time Machine as the target for the backup. In the Options section, you can specify source area to be excluded.

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Answer 3

dialabrain

Level 10

125,465 points

Apr 10, 2022 10:27 PM in response to Tesserax

Tesserax wrote:

What is the 2TB SSD formatted as: NTFS, HFS+, or APFS? If not already, it should be formatted as APFS and solely used for Time Machine backups.

FWIW, I believe the question is how to back up the external 2TB SSD to an external 8GB Time Machine drive.

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Answer 4

Apr 11, 2022 8:57 AM in response to dialabrain

Thank you, I will research how to reformat this disk as APFS.

As for your comment, "solely used for Time Machine" - this disk will be solely used to hold my graphic design files. I would like Time Machine to be able to access previous file versions in case of file corruption or if there is a need to return to an earlier version of the file.

You've been very helpful. I appreciate your time.

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