I “accidentally” started a backup via TM on my MBP by just choosing a new location för my backups (the shared folder on my NAS), logged in with my “ordinary” user account for the NAS - and it seemed to work fine? What is the difference (or consequence) compared to if I hade created a new user?
A separate user account for a (backup) service, or service account, has several purposes.
First is the quota. Second, you define the permissions (both file and application permissions) for the type of service, and last, the password.
Imagine you use an account that you use interactively to log on to your NAS and change the password in the future. You might not realize that this fails the service that uses the password. The same applies when the account is deactivated.
A service is an unattended activity that serves a specific purpose. You customize a separate account for that activity to ensure the best performance, continuity, and security. Service accounts are a standard procedure in business IT.
To configure quotas for the Time Machine backup of multiple Macs, you need either multiple accounts or multiple shared folders—not both. It depends on where you define the quota: on the shared folder or the account.
But you are free to do otherwise.
That post you refer to needs updating to include some changes in newer software, but I’m happy to hear it still works. And yes, I wrote that post.
Thank you for your reply and explanation about services. It makes sense.
So I created a new shared folder and three new TimeMachineUsers and defined a quota for each. However, I ran into the problem you mention in the post with entering credentials when trying to connect one of the new users.
I used the IP-address-suggestion to get the prompt for credentials, and the new user can connect to the server (after 3-4 attempts). But when I enter the new user’s credentials in the TimeMachine dialogue box it won’t let me enter the password. I get only to enter one single character then it sort of freezes. As a workaround I copy&pasted the password and it seemed to connect. TM says it is preparing the backup, but then gives up after 10-15min saying it cannot connect to the server.
I give up for now. The problem is definitely on my side as I have too little knowledge and maybe need to do some more reading and watching
Which version of DSM do you run on your NAS? From DSM 7.2.1 onwards, a new SMB advanced setting is recommended: SMB3 directory leasing + apply to all shared folders.
