Getting CrashPlan to work on Mac after JDK 1.7 upgrade

After upgrading my Mac to JDK 1.7, I noticed that CrashPlan stopped working. Given just how much trouble I got in a ways back when I lost a month's worth of pictures and videos of my son I'm now a belt and suspenders kind of backup guy ... the belt may be TimeMachine, but the suspenders are CrashPlan.

After working it out with their technical staff, it turns out CrashPlan is not compatible with JDK 1.7 on Mac which is rather unfortunate. And, having installed JDK 1.7, it was trying to use that version!

Getting it working is pretty easy however; most of the information is available in their recipe for starting and stopping the CrashPlan engine. The key part is that the com.crashplan.engine.plist file includes an entry where you can specify the path to the Java executable; with a bit of experimentation to find the right path, it appears to be working.

The only change I made to the file was to change the path; the first entry for the ProgramArguments key:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.crashplan.engine</string>
<key>UserName</key>
<string>root</string>
<key>GroupName</key>
<string>wheel</string>
<key>Nice</key>
<integer>20</integer>
<key>KeepAlive</key>
<true/>
<key>OnDemand</key>
<false/>
<key>RunAtLoad</key>
<true/>
<key>AbandonProcessGroup</key>
<true/>
<key>WorkingDirectory</key>
<string>/Applications/CrashPlan.app/Contents/Resources/Java</string>
<key>ProgramArguments</key>
<array>
<string>/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Commands/java</string>
<string>-Dapp=CrashPlanService</string>
<string>-Xmn10m</string>
<string>-Xms15m</string>
<string>-Xmx1024m</string>
<string>-DappBaseName=CrashPlan</string>
<string>-Djava.awt.headless=true</string>
<string>-Dfile.encoding=UTF-8</string>
<string>-Djava.net.preferIPv4Stack=true</string>
<string>-Dsun.net.inetaddr.ttl=300</string>
<string>-Dnetworkaddress.cache.ttl=300</string>
<string>-Dsun.net.inetaddr.negative.ttl=0</string>
<string>-Dnetworkaddress.cache.negative.ttl=0</string>
<string>-DCP_USER_NAME=</string>
<string>-DCP_USER_HOME=/Users/hlship</string>
<string>-cp</string>
<string>lib/com.backup42.desktop.jar:lang</string>
<string>com.backup42.service.CPService</string>
<string>CP_USER_NAME=</string>
<string>CP_USER_HOME=/Users/hlship</string>
</array>
<key>StandardErrorPath</key>
<string>/Library/Logs/CrashPlan/engine_error.log</string>
<key>StandardOutPath</key>
<string>/Library/Logs/CrashPlan/engine_output.log</string>
</dict>
</plist>

You will, of course, need to sudo to edit the file and to stop and relaunch the CrashPlan engine. Now, having set this up (and, coincidentally, renewed by annual subscription) my computer is happily chugging away, making the backups.