iPartition - Resize disk partitions without formatting

Nov 30, '04 10:18:00AM

Contributed by: robg

iPartition icon The macosxhints Rating:
10 of 10
[Score: 10 out of 10]

If you work with partitioned disks, there's a good chance you've eventually discovered that you gave too much space to one partition, and not enough to another. In the past, that meant a reformat, repartition, and reinstall process that would take a ton of time. PC users have an application called PartitionMagic that can do this work without erasing the disk in the process. Until recently, though, Mac users were stuck with starting from ground zero (which makes for a tedious and lengthy project). Not any more -- there are actually two products out there (that I know of) that can resize partitions without destroying data. The first is SubRosaSoft's VolumeWorks, which I have not used. The second is this week's PotW, iPartition.

WARNING: Resizing partitions on the fly can be very dangerous. You can lose data if things go wrong, even if the program works perfectly -- a power outage while writing changes to the disk would be disastrous. Make sure you have a backup before trying any program that offers partition resizing! In my case, I had my FireWire backup of the whole system, plus a burned DVD of my critical personal files ... and I copied a bunch of stuff to my PowerBook. You can't be too paranoid about backups!

On my machine, I have a boot/system partition that holds the OS and my user files, and then a bunch of other specialty partitions for things like audio, video, and graphics. Yea, I know it's not required and I don't get any speed gain, but it's just the way I prefer to organize things. Anyway, for a while now, my system/user partition had been filling up (less than 5GB free), and my smaller second drive was already bursting at the seams. After some looking around, I decided to replace the second drive with a 300GB Maxtor SATA unit. I moved all of my non-system and non-user partitions to the new internal drive, leaving a bunch of free space ... none of which was usable by the system drive, since it was all on the other partitions. That's where iPartition comes into play.

iPartition makes it brain-dead simple to move, delete, add, and resize partitions -- without reformatting first! I've used PartitionMagic, and while it's quite good by PC standards, iPartition takes ease of use one big step further. The iPartition interface is elegantly simple yet very powerful, as seen in the image at left (click the image for the big version). You select a partition to work with by clicking on it; it then slides out from the pie, and gains the markings shown in the image. To resize the partition, just grab the small white dot at the end of the extended line, and drag. The new size of the partition is always visible and constantly updated. Delete a partition by selecting it and hitting delete. Add one with the plus button in the toolbar. All of these changes are non-destructive -- when you make them, you're just putting together a plan for iPartition to work with. The Operations button in the toolbar opens a window that lists every change that you've requested, and it's updated in real time as you make further changes. At any time, you can cancel and revert to the disk as it currently exists.

If you're a deeply technical type, you'll also love the Inspector window, where you can see and modify things like "Can Chain," "PIC Boot Code," "First Boot Block," and "Flags." I have no idea what any of those are, but they can be changed by those who do know. You can also easily make your disk unusable by modifying some of these settings, so I stayed well away from them.

Once you've got everything set up the way you want it, just click Commit, read and heed the warning about data backup, and then watch it work. I deleted four partitions, resized two others, and added a third. The Commit process took something less than 15 minutes -- perhaps much less, as I left the room during this stage, and it was done when I came back.

iPartition did exactly what it claimed to do, and did so with a pleasant and easy-to-understand interface (Disk Utility could learn a trick or two from the interface design). It probably turned what would have been a five or six hour ordeal (even with good backups, it still would've taken a while to copy and verify the functionality of 150+gb of data) into a simple one-hour project. And that hour includes the time I spent learning the program. So while $35 may seem expensive in comparison to typical PotW products, it's actually quite cheap -- PartitionMagic sells for twice that amount. And my time certainly has a value; the hours of work saved make it well worth the cost.

But please heed the warning in the app, as well as the one in this hint -- if you are going to do any mucking about with your partitions, back up first!. Preferably a few times to a few places...

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