I’d like to set up multiple computers to use TM on one shared NAS. Is it better for all of them to use the same login account and password to access the NAS, or should they each have their own? We’re all in the same family, so it’s relatively low security 
Different accounts for each Mac and a single shared folder. Why? Not because of security but for quota settings.
I assume you use a separate account for the user to access the NAS and another for the TM backup. The TM account, unique for each Mac, only has a quota and restricted access to the TM backup folder.
I’m sort of new to this, so trying to figure out exactly what I need!
I think it would be multiple shared folders on the NAS, one for each TM. Right now, I think there’s a single account to access the entire NAS. Rather than have an account for each computer to access their own shared folder, can I set it up so there is one account that all computers use to backup to the NAS? I think you can set the quota when you set up the folder, right?
Assuming you have a Btrfs volume (not Ext4), you can set a quota on the shared folder and use a single account.
I do not often self-promote in forums, it is Will’s forum after all, but this is a post I made in the past and one of the few that discuss multiple Macs to a single NAS. You might find some helpful hints on setting this up.
Thanks for this!
In your tutorial, you write this:
Since each Mac with Time Machine creates a separate backup file, there is technically no need to create a separate shared folder for each Mac. All backups from your respective Macs can go into the same shared folder for Time Machine backups.
Because you must limit the maximum size of your backup with a quota, and we assign quotas to the TimeMachineUser account that we use for the backup, I advise you to create a user account per Mac for its Time Machine backup. It makes sense to include your Mac’s name in that user account for easy identification.
You can, however, create multiple shared folders, one for each Mac. The benefit of this additional step is a complete separation, assuming you only give one TimeMachineUser access to each shared folder. Now, no TimeMachineUser account can affect (read: delete, change) another Time Machine backup file.
For my purposes, is it fine to have multiple shared folders, one for each Mac with its own quota, but one user account? I think there’s very low risk that a family member will go in and mess around with someone else’s backup but a high risk that my life will be complicated by more accounts!
Hi, yes, it is perfectly fine to set up your TM backups with a single account for backup and multiple shared folders, one for each Mac. Just to keep it simple.
Great, thanks!
I was fiddling with some things and somehow, I can no longer connect to it using TM. It’s possible that I inadvertently changed the password.
That said, somehow, the DSM window is still open and connected to my unit.
How do I change the password? Or, can I even have an account with a password?
On a related note, is the password for my NAS administered through DSM or through macOS? And is the password for my NAS the same as the password that I use to access DSM?
(Sorry for all the questions!)