As I’ve posted, I’ve always been running tight on disk space on this MacBook Pro. Even after going through my Documents folder and using AppZapper on applications I no longer want (it gets all the stray bits, as well as the application itself), I only have 21 GB available on a 120 GB drive. I know it’s probably silly, but I like having at least 20% of a drive free. Preferably more. This evening, I downloaded DiskInventoryX to try and figure out where everything is.

The results:

• Assorted work/personal documents of varying kind: 12.6 GB C3-related stuff is the majority of it. Not entirely negotiable to archive off-disk. I find I still have to pull up really old documents from time to time. We’re starting to use Box and Basecamp for a lot of our work product, so that helps.
• Parallels Virtual Machine: 11.7 GB. When I was using Windows XP more, I increased the disk to accommodate my ever-expanding Outlook files. Now that I only use Windows XP for IE-only websites, Quicken, QuickBooks and some Salesforce utilities, I can go back to the default 8 GB size. But that would mean starting a fresh VM and reinstalling everything. Just haven’t been in the mood.
• iTunes Library: 11.5 GB. I winced at the thought of one of those new super-capacity iPods. Sounds great, but where would I store the data locally? I have an external Firewire drive, and of course I could move my iTunes database off to there. But it’s a standard external drive which means it doesn’t travel with me. I’ve hesitated to move anything to it that I may want to get to when I’m not home. I’m seriously considering getting a portable drive that I can keep in my bag and keep plugged in at all times. Then I can move data like this off to it. But are those drives reliable for day-to-day use? Eric has toasted a couple.
• iPhoto Library: 7.7 GB. Same issue as above. Fine to keep it external when I’m home, but it would be completely inaccessible otherwise. This may be a worthy concession, since I don’t access old photos nearly as often as I sync my iPod.

After that, the next largest folder takes just 286 MB and isn’t worth worrying about, and it goes down from there.

My largest disk-space hogs total just 43.5 GB. My Applications folder takes 8.1 GB. 51.6 GB accounted for. That means that assorted small files that would take years to clean up effectively are filling 35.5 GB of space. I’m thinking I will save a few GB by dumping GarageBand, iMovie and iDVD off to the external. I never use those applications and I can see the sample files and themes are taking up space.

Lesson learned: No matter what, buy a notebook computer with the largest internal disk capacity you can get. I could have gotten a 160 GB drive. I’m kicking myself now that I didn’t. RAM is easy to upgrade/add on. Capacity isn’t. Upgrading an internal drive on a MacBook Pro is not trivial.