I noticed that on some of my large clients servers, crash plan keeps crashing. Somewhat symbolic in it's name :)

This not only happened in the front end GUI but also the backend.

and normally if the server had very very big backup sets of a few TB or more.

I reviewed the log files and have found that when crash plan runs it tries to compile a list of changes that have been made. If this catalog was very big it would crash.

If you stop crash plan

$ sudo launchctl unload /Library/LaunchDaemons/com.crashplan.engine.plist 

 

If you modify launchd item

$ sudo pico /Library/LaunchDaemons/com.crashplan.engine.plist

and modify the following string

<string>-Xmx512m</string> to <string>-Xmx3072m</string>

then restart the launchd item 

$ sudo launchctl load /Library/LaunchDaemons/com.crashplan.engine.plist

The backups will now work. What we have now done is allocate 3GB of memory to the application v’s the 512MB that were allocated to it originally.