huge Time Machine backups for no reason

[ignatius345]

I'm seeing some really large Time Machine backups, even though I haven't done much. They seem to appear sporadically. Yesterday I had one that took several hours to complete, and now I've got another that says it's copying 32 GB of files. Meanwhile, a lot of the intervening ones have been pretty small.

I haven't updated the OS in the past day, no huge downloads, no large files or anything modified. At most I've been modifying a few spreadsheets, a bit of emailing, stuff like that.

In the old days of HFS+ Time Machine backups, I'd run a utility I had called TimeTracker that would let you inspect what had changed in each backup, but it doesn't seem to work under APFS.

Curious to hear if anyone else is seeing behavior like this.

 

[J0m083]

Can it be that TM (incorrectly) includes a mounted disk in the backup? I've seen that happening. Check TM/Options, estimated size of backup is then much larger as normal.

 

[ignatius345]

I do have an external in the mix (it has my Photos library and some other media). But still, I definitely didn't have 32 GB of stuff change.

Anyway, it seems to have settled back into doing normal, appropriately-sized backups now, but I do wish Time Machine was a bit more transparent about what exactly it's doing sometimes.

 

[AppleSmack]

If you're using an app that provides a clipboard history, that can lead to some chunky incremental backups.
Also, when I once dabbled with crypto, the ever-updating blockchain caused huge incremental backups.
In brief, do you have an app that creates or updates a large cache?