More than 1 physical HD for a single Time Machine backup?

[Rico Muerte]

Can 2 or more physical drives be used for a "single" time machine back up?

Ive got a 2012/5,1 cMP with 4 physical drives - 1 for the OS/apps, 1 for general/personal files, 1 for all music recording, & 1 for time machine.
My time machine drive (4TB) is nearly full & could not complete the latest back up. I've got a few smaller drives around & wanted to know if I could use one in addition to the current TM drive for back ups.
Once again, 2 different physical drives for 1 TM backup...?

Thanks

 

[Bigwaff]

Not really. Each drive will be an independent backup drive. Post the exact error message you get when TM fails. TM will purge the oldest backups to make room for new ones. What version of macOS on cMP? Is your TM drive formatted HFS+ or APFS? Your TM drive should be at least 2x the storage size of the combined drives being backed up, if not 3x/4x.

 

[Fishrrman]

OP wrote:
"Ive got a 2012/5,1 cMP with 4 physical drives - 1 for the OS/apps, 1 for general/personal files, 1 for all music recording..."

Interesting.
I have a 2024 Mini, with the internal drive "hard partitioned" 4 ways:
- boot
- main
- media
- music

I DO NOT use time machine, however.
Instead I use CarbonCopyCloner to back up the 4 volumes.
My main backup is an external SSD, again partitioned into 4 volumes.
I also maintain backups (again, by CCC) on other drives in other locations.

Backups created with CCC do not forever "grow" in size (eating up disk space) as do backups in tm. However, CCC also offers something called the "safety net" which DOES archive older versions of changed files (it's enabled by default but you can turn it off, which is what I do).

There is also SuperDuper, which is a little "less-featured" than is CCC, but still does basically the same thing.