Multiple External Drives, swapping Time Machine questions

Jul 1, 2011
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Your Mac's Specs
27' iMac, 2.8 GHz Intel Core i5, 16GB Ram. 10.8.2 OSX
Hello Everyone!

Been a while since I posted here. But everything is just rolling along nicely! I guess I've been busy "just working" my iMac to really need to post anything...YEEHAA...still love this thing.

Anyway, on to my question.

I had a 1TB drive before I got my Mac, that I basically copied what I needed off of it onto my Mac, then reformatted it to only work with my Mac, then copied all my stuff back over. So I have a 1TB drive, that has about 150gig used right now.

I also went out and bought a 2TB drive to use as my Time Machine drive. Now I'm not sure if I misunderstood or not, but I was under the impression that TM would continue to make backups hourly, daily, etc...until I basically filled up the drive and would then start deleting old data. Well, not sure if it is doing that or not. Here is my situation.

I right click on my TM drive, and "Get Info" and it shows available 1.86 TB. It has been resting at that point (give or take a point) for quite some time now.

I can double click on TM and it does show a timeline going back to July (when I first got this TM drive) so I do believe it is working, but perhaps it just isn't making full backups hourly like I thought it would.

I should note, that I have become a organizational monster with my iMac and keep it VERY clean so I am constantly moving old docs, movies, etc that I am not using much off of my iMac and onto my 1TB drive.

So maybe that is why my TM drive isn't really eating up much space because I'm not really changing much on it.

Ok, so I've said all of that to say this:

I think I might want to move all of my data off of my 1TB drive (150gig worth) onto my iMac temporarily to then reformat it and use it as my TM drive, then reformat my TM drive (the 2TB one) to use as my regular data storage that I have.

1) Do you all recommend doing that?

2) If I do that, is there any way to transfer the last few months of Time Machine backups to the 1TB drive that hasn't been my TM backup?

Since I'm still fairly new at this whole Mac thing, I just wanted to make sure I wasn't missing something or overlooking something obvious.

Any pointers or opinions are welcome! Thanks and God bless you all!


TM doesn't make full backups each time. It makes a full backup the first time, then on subsequent backups only copies what has changed, and uses aliases (think "shortcuts") to hold the unchanged files in proper place for you to see when you open up each backup. So if you aren't making many changes, it can take a long time for a big drive to fill up with TM backups. I think your idea is a pretty good one, myself. I don't know how to transfer TM backups because TM tracks where it is and what it has done. Maybe somebody else here can help you with that.

BTW, I'm a belts-and-suspenders man myself, so I use a portion of my external drive for a copy of my internal drive in addition to TM. I use Carbon Copy to clone about once a month.

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