SuperDuper! and copying Time Machine drives

[camner]

Over the years I've used SD! successfully a number of times to clone a TM drive when the drive ran out of room (or if I just wanted to use a newer drive). It's always been successful (AFAIK...)

I just ran across this from Carbon Copy Cloner's Knowledge Base which says not to use CCC this way "because Time Machine backup folders contain Apple-proprietary filesystem devices" (whatever that means).

So, CCC doesn't support cloning TM drives. Does SD! still do so? (I couldn't find a forum post newer than 2015 that addressed this.)

Thanks!

[dnanian]

I don't think they mean "devices". Time Machine backups are complex. They have millions of hard linked files and folders, and are also protected by the Time Machine kext.

We handle that up to 10.13.x. However, Apple may change the way TM backups are "protected" in 10.14 and later, and at that point we may not be able to copy them.

Note, though: Apple now allows you to have multiple Time Machine destination volumes, and disks are cheap. In addition, Time Machine is not intended to be an 'archive'. I would generally suggest two Time Machine destination drives for serious use (effectively backing each other up), and then starting a new one if you need more space.

[camner]

Thanks for the quick reply.

I think of SD! with my weekly (rotating for a month) full system cloning as my "backup" in terms of recovering from things like disk failure, system updates that went wonky, etc.

I then think of Time Machine as serving two purposes:

1. In between SD! clones to recover from, if needed
2. Archiving deleted files and previous versions of files

(And then I have a cloud backup for "house burns down")

What do you suggest for archiving purposes if it isn't TM?

And, if TM isn't for the purpose, what role do you feel TM plays in a backup strategy where SD! is used regularly?

[dnanian]

Time Machine gives you the ability to recovery changed and deleted files within a window. However, it's not an archive.

I would suggest a separate "archive" volume as an archive...and that should also be backed up.

[camner]

Thanks for the quick reply. Makes sense.

Do you have a favorite archiving app?

[dnanian]

When I want to archive something, I move it with Finder to an appropriate structured archive drive...