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I'm thinking of purchasing a hard drive for the time machine option on my macbook pro.

If I buy a large hard drive, can I still use it to store my own stuff or does it all get used up by Time Machine backups? Will it allow me to use the remaining space for my own stuff?

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up vote 3 down vote accepted

You might want to partition the drive. Otherwise, yes, Time Machine will eventually take up the entire drive. By partitioning it, you can reserve part of the drive for non-Time Machine use.

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There really isn't a reason to partition the time machine drive.... You can store content on it, without risk, harm or danger... – Benjamin Schollnick Nov 14 '09 at 22:23
Time Machine will hog as much as it can over time to prevent erasing backups. – Nerdling Nov 14 '09 at 23:23
Exactly, Nerdling. Thank you for finishing my thought! – Creepygeek Nov 15 '09 at 2:18
True, it will hog as much as necessary, but if your time machine partition is a reasonable size it won't matter... My 1 Tb drive has backups going back to 3/26/2009, and I have over 140 Gb of free space. Partitioning the drive is asking to run low on disk space when you need it. – Benjamin Schollnick Nov 15 '09 at 5:24

You don't need to partition a Time Machine disk. You can place anything you want on it, but that space that you use, can't be used by Time Machine.

Time Machine won't delete the content you place on the drive, but you don't want to modify anything in the Time Machine directory (backups,backupdb) or place anything in there....

If you partition it, sooner or later your want more space, especially if you don't really use the space on the partitioned drive that you "reserved" for yourself.

If want, you can take a look at some more Time Machine information here...

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Resizing partitions isn't a problem. gparted and diskutility to a lesser degree are both capable. – Nerdling Nov 14 '09 at 23:24
Yes, you are correct, you potentially can resize the partition... But that's like only giving your windows partition 30 Gb because you can always resize your boot camp partition. You will run low on disk space eventually. Since the Time Machine drive can be used as storage, why complicate things? Disk space is cheap. 1Tb FW 400 = $129. 1Tb FW 800 /Esata = $205. Internal is cheaper... Why skimp? This is your backup... – Benjamin Schollnick Nov 15 '09 at 5:29
@Benjamin: everyone has their own idea of what's expensive and what's not. However, you do make an excellent point - this is your backup after all - why skimp?! But the opposite to your argument also applies - eventually, Time Machine is going to use up the spare space that you will want for your 'other stuff'. – Steve Folly Nov 15 '09 at 12:38
If you put additional non-time machine data on the drive, that data will eventually take up space that Time Machine could use. But partitioning the drive is worse, because you won't consider it "bad" to use. What good is TM if you decide to put your itunes on the other partition. Now if the drive dies both your backup & itunes data would be damaged... It's rare on a Mac that partitioning is truly helpful, in my experience. – Benjamin Schollnick Nov 15 '09 at 12:52
@Benjamin: fair point. I think the answer is to allocate a disk solely for TM, and another disk for 'other stuff'. – Steve Folly Nov 15 '09 at 17:56

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