Should I create dedicated users and/or datasets for Time Machine?

[John Childermass]

I'd like to set up Time Machine backups from multiple Macs in my household (two Macs, each with a different user/owner, but this might increase) to my TrueNAS CORE system. I'm running TrueNAS-12.0-U8.1 but am ready to update to 13, especially if that makes any difference to this.

I've found a few older threads, but would like to check what the current advice is, please:

• Should I create a single dataset for all the Time Machine backups to go in, or one dataset for Mac1, and one for Mac2?
• Should I create dedicated Time Machine users on the TrueNAS system for the Time Machine backups? i.e. even if I already have configured User1, the owner of Mac1, for general access to storage on the TrueNAS system, should I create a dedicated user like "User1-timemachine" or "Mac1-timemachine" solely for the Time Machine backups from Mac1 (and the same for User2 on Mac2)? Or could I just use the existing general-purpose User1 and User2 credentials?

For both questions, if either option could in principle work, are there pros and cons for each choice?

In case it makes a difference: I'd like to configure permissions so that the two users can't see each other's Time Machine backups, and I'd like the option of setting quotas for each Mac's set of backups if needed (even if I might not need to impose quotas immediately).

Also, I couldn't find anything about Time Machine in the TrueNAS CORE documentation, even though there's something in the old FreeNAS documentation. Does it still work OK, and is there any reason it's not there any more, or am I just missing it?

Thank you in advance for any tips!

 

[Glorious1]

Set up a single dedicated Time Machine dataset with an SMB share. There is a setting for multi-user Time Machine; use that. Each user will only see the Time Machine dataset, but in reality when they first use it, a sub-dataset will be automatically created for them, and they won't have access to anyone else's. It works quite well in my experience.

There is a recommendation to have separate Time Machine users for each user, but I don't see the point; it seems like needless complication. We just use our own user to access Time Machine and it works fine.

EDIT: now I'm recalling the point about separate Time Machine user accounts for each machine - you're backing up a machine that could have multiple actual users. That's not a compelling reason in our case.

 

[John Childermass]

Thanks @Glorious1 ! I'll try the single Time Machine dataset with the "Multi-user Time Machine" setting. I hadn't properly understood that this (auto-creation of individual sub-datasets, etc.) was what this setting was for.

About the dedicated Time Machine user accounts, I suppose the idea is that because the Time Machine process backs up all of Mac1, which may include multiple actual users User1, User2, etc., in principle one shouldn't use just the User1 (or User2) credentials for the Time Machine backups. It's also not a majorly compelling reason in my case (the Macs are actually single-user) but I might set up a dedicated "Mac1-timemachine" user on TrueNAS just to keep things compartmentalised.