Huge TM Backups

Over the last 3/4 days TM has backed up about 150GB to my WD 2TB Partition which has now 980GB free, so no panic yet but it's now half full. My 3TB Fusion Drive has 2.42TB free, so no panic there either.

All I have really done during this time is to clean up/add/delete Keywords in Lightroom 5 to some of the DNG files.

I know now that DNG files get re-backed up if there are any changes made to them and I should have just backed up the Catalog as usual, but when I enter TM and compare the Pictures folder last week, before my LR clean up, to now there is only a 16GB difference.
Where is all this data coming from?
Any suggestions as to how I can find out and the best way to deal with it would be very helpful.

Thanks
Graham

I don't have a definitive answer for you regarding which of your data is getting backed up, however, from our experiences with Time Machine, it will detect and backup changes that are not easily seen. An example would be when deploying a virtual machine which can encompass several GB or more. A small change within the VM will cause Time Machine to backup the entire VM. I don't know if that info helps or not, but you might start by excluding some things from your backups that you suspect to see if that reduces the amount.

chscag said:

you might start by excluding some things from your backups that you suspect to see if that reduces the amount.

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Precisely! I have excluded the entire iTunes library from TM backup (as it gets cloned and imaged daily, by CCC), and that makes a huge difference

Thanks chscag for your reply. I don't have a VM and I have now excluded LR from TM to see if that makes a difference. It must have been caused by the DNG files as I didn't do anything else major.

Is there a good app that can show just what TM is backing up?

Thanks David too, I've just excluded itunes as well to see if anything there is amiss.

Is there a good app that can show just what TM is backing up?

Click to expand...

Not directly, however, there are several good free utilities which can show what's where on your hard drive:

Grand Perspective

Disk Inventory X

GrahamHCB said:

I've just excluded itunes as well to see if anything there is amiss.

Click to expand...

But please make sure you have other backup routine for iTunes in place, it wouldn't be wise to leave it (or anything else, for that matter) without backup. A simple clone is sufficient, and won't take more space than original.

For me, I decided trying to figure out the what, why, where and how TM does it's thing to be a waste of time. Especially considering a I also keep a bootable clone. I keep my TM backup until the drive fills up - then delete it and start over again. That's typically about once a year.

chscag said:

Not directly, however, there are several good free utilities which can show what's where on your hard drive:

Grand Perspective

Disk Inventory X

Click to expand...

Thanks chscag I'll look into those two apps.

MBP17•David said:

But please make sure you have other backup routine for iTunes in place, it wouldn't be wise to leave it (or anything else, for that matter) without backup. A simple clone is sufficient, and won't take more space than original.

Click to expand...

Thanks David

Yes my itunes, along with everything else, is cloned regularly with SuperDuper.

bobtomay said:

For me, I decided trying to figure out the what, why, where and how TM does it's thing to be a waste of time. Especially considering a I also keep a bootable clone. I keep my TM backup until the drive fills up - then delete it and start over again. That's typically about once a year.

Click to expand...

Thanks bobtomay

It's pretty frustrating to try and work out just what etc TM does. I quite like your idea of deleting the TM drive when it's full and starting again, I also keep a bootable clone so maybe that's the way I'll go too.

You also might want to look into TM's frequency - for me, with daily CCC and on-demand rsync backups, weekly TM is more than sufficient.

+1 for what MBP17*David said. I use CCC to clone my drive once a day (middle of the night, actually) and I use TimeMachineEditor to set TM to also run once a day, also in the middle of the night. The backups go to different drives, and the CCC backup is bootable.

Time Machine backs up everything. After that, it simply backs up everything that has been modified by the user in the intervening time since the last backup. Some apps (particularly VMs like Parallels) "touch" very large files frequently, so that gets backed up nearly every time you run Time Machine! Excluding VMs and the other exception you noted is a good move.

Those who use iTunes Match ($25/year, a number of benefits attached) can skip backing up their iTunes library (well the music part anyway), as you've essentially got an iCloud backup.