Why are my Time Machine backups so big?

TheGreenBastard said:

The first time I backed up (a couple days ago), the initial backup was about ~190GB, and every time (every hour) after that, backups have been ~100MB, but the last few hours the backups have been about ~70GB each time. What's up with that? I haven't downloaded anything or changed anything in the past few hours.

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Do you use any VMs? Like Parallels or Fusion?

TheGreenBastard said:

Yup, but for a couple months, so I'm unsure as to why the backups are so big all of a sudden. Nothing has changed on the VM (downloads).

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How big is your VM OS? It sounds like to me it's backing up the VM changes (which is one big file, so the whole thing gets backed up). I stopped having this backed up because my VM partition was 100GB, and it wanted to back up 100GB every night.

I think you should go into the Time Machine preferences and have it exclude the VM (not the application, but the ACTUAL VM), and then run a backup and see if that fixes it.

TheGreenBastard said:

I've been using the VM for over a month now, other than the first backup, this strange large backups of ~70GB happened only the last couple of days. Anyway, I think I'm going to disable backup for Parallels.

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Sure sounds like the VM, in any case. Let us know how you do when you disable it.

"but the last few hours the backups have been about ~70GB each time. What's up with that?"

Suggestion:
If you want clean backups that are "normally sized" and truly reflect what is on your internal drive, stop using Time Machine and switch to CarbonCopyCloner instead.

CCC backups are fully-bootable exact copies of the source drive. They don't "grow" in size any more than your source.

You can set up CCC to clone the recovery partition as well, and CCC can now "archive" older versions of changed files (similar to what T.M. claims to do).

The major difference with CCC is that there isn't a stupid "on/off" switch. You must set it up and run it "wilfully".

T.M. is "backup for dummies". Just turn it on, and you're all set, right?
The only problem is that if you read this forum, you'll regularly see posts from folks to the effect: "I can't access my T.M. backup…" etc., etc.

A CCC backup is instantly mountable, instantly bootable, with all your files right there in front of you in POFF (plain old finder format).

(just waiting for the replies that say, "T.M. is intended for a different purpose… blah, blah…")

The purpose of backing up is to have a backup at a moment when you desperately need it.

When that "moment of extreme need" comes, you'll be better served by having a CCC backup close-at-hand, than with a T.M. backup…

Fishrrman said:

(just waiting for the replies that say, "T.M. is intended for a different purpose… blah, blah…")

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I'll bite! TM gives you a version history. Want to recover a file you deleted or modified a year ago? TM will do that, CCC won't.

That said, I'm backup paranoid. I use TimeMachine, SuperDuper! (basically the same as CCC for those that don't know), and CrashPlan. And my SuperDuper! clones are to two alternating backup drive sets, one kept off-site.