Will a new backup job, for an existing organisation, necessarily write a complete new copy of that job's content if...?

[burstattack]

Guess my summary-writing game isn't as good as I thought it was. End of the sentence was supposed to be "it's pointed at an existing, up-to-date repository?"

Our VB365 instance has long been configured as "one job that backs up all types of content (Mail, Archive, OneDrive, Sites, Teams) to a single repository and runs once a day". Recently I split out one or two mailboxes that need to be backed up more frequently.

What I'm thinking now though is that
- Archive mailboxes don't need to be backed up every single day. Maybe once a week is enough.
- Personal sites probably don't need to be backed up at all.
- Mail would be better off split into different jobs for users and non-user objects.

That way, I can both save some time in the nightly job and have a bit more flexiblity around what's backed up, when, for how long.

My concern though is that VB365 isn't as nice as VBR is when it comes to redefining jobs and working with existing repositories. I know that new jobs require a full backup.* I'm worried that if I carve out some of the above workload into a new job, even if I point it right back at the existing repository where it has data all the way up until last night, VB365 is going to look at it, pretend it doesn't see anything, and then merrily write a fresh 2-3 TB of content of "everything from year zero", blowing out the free disk space.

Is that the case, or will it take a full backup, see that the data it needs is already present, be happy with that, and just write the most recent unrecorded changes?

* I did have to repoint the main job away from and then back at the same repo a couple of weeks ago, and I noticed it did indeed work the way I wanted it to (took a full backup but didn't write everything all over again). I'm not sure if this holds true for new jobs though.

[Mildur]

Hi Simon

Welcome to the forum.

A new Job won‘t download everything again, if pointed to the old repository which contains already all data. Only new and changed objects will be backed up.
The first run will take longer, because it has to run through every item in M365 and check if it‘s already in the repository.

Thanks
Fabian

[burstattack]

Hi Fabian,

Thank you for the welcome and for the informative answer. I'm very glad to hear that!
Now I can finally reconfigure those jobs into a more practical structure.

Regards
Simon