What exactly is Time Machine backing up?

[bazookaman]

Yesterday around midday, TM was backing up around 60gb of 70. So by the end of the day, it was done. I went home. Didn't even take my laptop out of the bag. Came in this morning. Plugged it in, and now TM has started backing up 11gb of 72. WTF? Where did 72gb magically appear after I closed my computer yesterday???

[Sarcany]

Virtual machines and large database files are usually responsible for backups like that.

Do you run a virtual machine on that Mac or use an old version of Outlook?

[bazookaman]

Hmmm..I bet thats it. I have two virtual machines, but the only one I use frequently is around 65gb. So that means its probably backing up that and only 5 or so gb of random stuff. That makes me feel better.

[NewtonMP2100]

....Marty.....McFly.....???

[rich in distress]

I would consider, if at all possible, running VMs from an external SSD, and backing that up at specific intervals.
Imagine a couple of cookies triggering such backup activity...

[S. Pupp]

I leave my virtual machines on my internal drive, and enter them as exceptions to backup in the Time Machine control panel. I back up the virtual machines from time to time by copying them to an external drive.

[rich in distress]

Pretty nifty S. Pupp!
I hope I don’t forget it next time I setup Time Machine.
Right now iCloud is enough for my needs.

[bazookaman]

S. Pupp wrote:
I leave my virtual machines on my internal drive, and enter them as exceptions to backup in the Time Machine control panel. I back up the virtual machines from time to time by copying them to an external drive.

You know. Apparently I knew that...at some point in the past. B/c I just went to my TM options and there it was. The virtual drive that I DON'T use that much was excluded. So I just added the other one too.

[S. Pupp]

[rich in distress]

Did TM keep the old backup of the recently excluded VM?
Backup accordingly.