Reducing CrashPlan's Disk Space Usage on OSX

November 4, 2011

I have CrashPlan backing up almost every file on my Hackintosh, and when CrashPlan runs, it caches a ton of data so it can run faster. However, they don't let you configure where that data is stored. In my case, I'm backing up around 1TB of data, and thus the cache is a whopping 8GB. 8GB might not seem like that much these days, but when it's sitting on your small SSD, it's quite annoying. Fixing this problem was pretty easy, and since plenty of people were complaining about this on their forums in different threads, I thought I'd post my simple solution here.

First, you need to have a second drive connected to your system that you'd rather have hold the cache. If you have this, then this solution should work for you:
1. Close CrashPlan, as you normally would.
2. Stop CrashPlan's background service by typing: 
sudo launchctl unload /Library/LaunchDaemons/com.crashplan.engine.plist
3. Remove the Cache:
rm -r /Library/Caches/CrashPlan
4. Create a simlink: 
ln -s /Volumes/OtherDrive/path/to/new/cache/ /Library/Caches/CrashPlan
5. Start CrashPlan's background service: 
sudo launchctl load /Library/LaunchDaemons/com.crashplan.engine.plist

6. Restart CrashPlan

This should free up a whole bunch of space on your startup disk. Enjoy!