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This article applies to Code42 for Enterprise version 4.

Code42 Support

Large engine_output.log (Mac)

This article applies to Code42 for Enterprise version 4.


In some cases, a large file selection (over 1 TB or 1 million files) can cause the CrashPlan app to run out of memory. This can cause the engine_output.log file to become very large. Adjusting the maximum amount of memory allocated to the CrashPlan service can resolve this issue.


CrashPlan app on Mac OS X backing up a large file selection


  • CrashPlan uses memory up to the maximum allotted. The maximum is used only if it is needed.
  • Code42 typically recommends allocating 1 GB (1024 MB) of memory per 1 TB of storage (or per 1 million files). Although CrashPlan only requires approximately 600 MB of memory per 1 TB of storage (or per 1 million files), our recommendation is intended to account for growth in your file selection.
  • If you uninstall and reinstall the CrashPlan app after increasing allocated memory, the setting will revert back to the default value of 1024 MB.

Sample recommendations

Backup Selection Size Recommended Memory Allocation (MB)
Up to 1 TB or up to 1 million files 1024 (default)
1.5 TB or 1.5 million files 1536
2 TB or 2 million files 2048
2.5 TB or 2.5 million files 2560
3 TB or 3 million files 3072

Memory limitations

You should not allocate more memory to CrashPlan than the maximum supported by your computer. For example, if your computer has 8 GB of RAM, you shouldn’t allocate more than 8 GB (8192 MB) to CrashPlan.

Windows XP and Windows 32-bit operating systems
If you are running the CrashPlan app on Windows XP or Windows 32-bit operating systems, we recommend limiting the amount of memory allocated to the CrashPlan app:
  • Windows XP: If you experience issues when trying to open or use the CrashPlan app, reduce memory allocation to 768 MB or 512 MB.
  • Windows 32-bit: On computers running a 32-bit Windows operating system, programs are limited to a maximum of 2 GB of RAM. After accounting for other resources required by your system, this limits CrashPlan's maximum memory allocation to approximately 1200-1500 MB. If you are running a 32-bit operating system, we recommend allocating a maximum of 1536 MB of memory to CrashPlan. Alternatively, you can remove files from your backup selection to reduce the size of your backup archive.

Recommended solution

If you are able to open the CrashPlan app, you can use the command-line interface (CLI) to allocate more memory.


  1. Open the CrashPlan app
  2. Double-click the CrashPlan logo in the upper-right corner
  3. Enter the following command, using a value appropriate for the size of your backup selection (for example, 1536 for a 1.5 TB selection):
    java mx 1536, restart
    The CrashPlan app closes
    Deauthorize app
  4. Open the CrashPlan app and sign in

Alternative solution

To adjust the memory allocation for the CrashPlan app if you are unable to open the app, use this solution.


  1. Open the Finder.
  2. Go to Applications > Utilities and open Terminal.
  3. Stop the CrashPlan service by entering this command:
    • Installed for everyone (default):
      sudo launchctl unload /Library/LaunchDaemons/com.crashplan.engine.plist
    • Installed per user:
      launchctl unload ~/Library/LaunchAgents/com.crashplan.engine.plist
  4. If prompted, enter your password, then Return.
    Your password does not appear as you type.
  5. Open the command line text editor by entering this command:
    • Installed for everyone (default):
      sudo nano /Library/LaunchDaemons/com.crashplan.engine.plist
    • Installed per user:
      nano ~/Library/LaunchAgents/com.crashplan.engine.plist
  6. Using the arrow keys on your keyboard, find the line that contains the following:
  7. Change the number to a larger value, depending on the size of your file selection.
    • See guidelines above for recommendations.
    • For example, if you are backing up 1.5 TB of data, we recommend setting this line to -Xmx1536m
  8. Press Control+X to exit the text editor.
  9. Press Y to confirm the changes.
    The prompt "File Name to Write" appears.
  10. Press Return to save to the existing location.

  1. You can delete the large engine_output.log file from the service log directory at this time:
    sudo rm /Library/Logs/CrashPlan/engine_output.log
  2. Start the CrashPlan service by typing:
    sudo launchctl load /Library/LaunchDaemons/com.crashplan.engine.plist
    Please note, you may be prompted to re-enter your password after entering this command.
CrashPlan menu bar closes
Stopping the CrashPlan service may cause the CrashPlan icon in your Mac's menu bar to quit. You can relaunch this icon from Settings > General by clicking Launch.

Under the hood

When a large file selection causes CrashPlan to run out of memory, the engine_output.log accumulates errors that cause it to grow in size. By increasing the maximum amount of memory that CrashPlan app can use, you can eliminate these errors and keep the log file to a reasonable size.