Originally published Friday, January 6, 2012 at 12:00 PM

Where did all that disk space go? DaisyDisk helps you tidy up

DaisyDisk scans your hard disk — or any other connected volume — and reveals, in a clever starburst-style graph, which files are taking up the most space.

Special to The Seattle Times

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When I bought my current MacBook Pro in 2010, I wasn't just looking forward to the promise of speed over my older laptop, but also a capacious 500-gigabyte hard disk.

Now, with the clock rolling over to 2012, I found myself wondering where all that free disk space went. With only 10 GB free, I needed to give my drive some breathing room.

I've gone down this road before. Digital photos and videos are the easiest-to-identify culprits for consuming gigabytes, but I've been good about storing my media on an external drive. What else was consuming all that space?

To find out, I bought DaisyDisk ($19.99, but on sale for $9.99 at the time I'm writing this; from the Mac App Store. DaisyDisk scans your hard disk — or any other connected volume — and reveals, in a clever starburst-style graph, which files are taking up the most space.

You can drag files to an icon called a Collector and delete them from within DaisyDisk without having to track them down in the Finder. Or Control-click an item and choose Show in Finder to locate it immediately; that's helpful when you want to copy things to another drive.

In my case, some usual suspects cropped up, like movies in iTunes that I forgot to copy to the Mac mini I use as a home media server. I also found two old unused VMware Fusion virtual disk images I could move to another drive.

But the biggest surprise revealed itself to be nearly 60 GB of iOS device backups.

When you sync an iPhone, iPad, or iPod touch, iTunes creates a backup on disk. My collection may be larger than most, since I had backups from devices loaned for review, as well as several test backups of my own devices from when I was writing my books about the iPad.

To safely delete these, I switched from DaisyDisk to iTunes, opened the iTunes preferences, and clicked the Devices icon to reveal a list of stored backups. Then, I removed old ones by selecting them and clicking the Delete Backup button.

I've used the free utility GrandPerspective ( in the past, and that continues to work fine, but without the polish of DaisyDisk.

You might think this just an exercise in computer housekeeping for the new year, but a too-full hard drive can lead to sluggish behavior when you're running memory-intensive applications that take advantage of virtual memory (where the computer uses free disk space to supplement RAM).

Paring down one's disk is also important if you're considering buying a MacBook Air, or choosing to equip a new Mac with an optional SSD (solid-state drive). Because an SSD contains no moving parts — it's an array of memory chips — performance is dramatically faster than a typical hard disk.

In fact, colleagues have told me t the best way to speed up an older Mac is to replace the hard disk with an SSD. You can buy them individually, as you can buy hard disks.

But SSDs are still lagging behind in capacity. The largest models approach 500 GB, but for that you can pay as much as a thousand bucks.

Drives of 256 GB are the practical high end, included in the high-end MacBook Air and as build-to-order options for the iMac, MacBook Pro, and Mac mini; Apple offers a 512 GB SSD option for the Mac Pro, running a cool $1,250 to replace the primary hard disk and $1,400 each to fill subsequent drive bays.

If you're contemplating a Mac with an SSD, or replacing a hard disk with an SSD, chances are you'll need to tidy up what's taking up space on your current hard disk.

I haven't yet taken the SSD plunge. I need the space for my projects, and carting around an external hard drive isn't ideal.

But using DaisyDisk has helped me cull unnecessary files so that I'm not tempted to replace my 500 GB drive with a 750 GB or 1 TB drive. I suspect the move to SSDs as the primary drive for most Mac models will happen this year or next, so I'm comfortable waiting. For now.

Jeff Carlson and Glenn Fleishman write the Practical Mac column for Personal Technology and about technology in general for The Seattle Times and other publications. Send questions to More Practical Mac columns at

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