Using Cluster Storage

By default, the Apple Qmaster distributed processing system saves temporary process files in the /var/spool/qmaster/ directory on the cluster controller. You can also choose any other location on a local disk for this scratch storage. Computers in the cluster will access this location as needed.

Selecting a Cluster Storage Location

Follow the steps below to change the cluster storage location.

To select a new storage location for a cluster
  1. On the cluster controller, open the Apple Qmaster pane of System Preferences.

  2. If any Apple Qmaster services are enabled on this computer, click Stop Sharing to temporarily turn them off.

  3. Click Advanced to open the Advanced pane.

  4. Click the Set button next to the Cluster Storage field.

    Figure. Cluster storage Set button in the Advanced pane in the Apple Qmaster pane of System Preferences.
  5. Navigate to the folder in the dialog, select it, and then click Choose.

    Note: If you are using the default This Computer setting in the Cluster pop-up menu in the Compressor Batch window and you choose Cluster Storage as the destination, the output file will be copied to the Source location.

Cluster Storage Capacity

If you are processing large source media files that exceed the available storage space on the startup disk, you may run out of storage space on that disk. There are a number of things you can do to address this.

  • Change the cluster storage location to a disk with more free space. For more information, see Adjusting Cluster Storage Settings.

  • Configure cluster storage settings to delete files more frequently. For more information, see Adjusting Cluster Storage Settings.

  • Compressor users can set Cluster Options preferences (choose Compressor > Preferences) to “Never copy source to cluster.” For more information, see the Compressor User Manual.

Adjusting Cluster Storage Settings

Follow the steps below to change scratch storage settings for a cluster.

To change cluster storage settings
  1. On the cluster controller, open the Apple Qmaster pane of System Preferences.

  2. If any Apple Qmaster services are enabled on this computer, click Stop Sharing to temporarily turn them off.

    Note: Do not attempt to change the cluster storage settings while the cluster is turned on.

  3. Click Advanced to open the Advanced pane.

  4. Configure the following optional settings:

    • To change the cluster storage location: Click the Set button next to the Cluster Storage field, then navigate to the folder in the dialog and click Choose.
    • To change how often cluster storage files are deleted: Enter a new number in the Delete Files Older Than N Days field.
      Figure. The Delete Files Older Than N Days field, the Cluster storage Set button, and the Stop Sharing button in the Advanced pane in the Apple Qmaster pane of System Preferences.
  5. Click the Start Sharing button to restart the cluster.

Cleaning Up Cluster Storage

If you are using cluster storage and an error occurs, partial files may be left on the designated cluster storage location. Check the designated cluster storage location to make sure no partial media files are left there. If you find partial media files, delete them and submit the job again.

QuickTime Reference Movies

If you submit a reference movie for distributed processing, the Apple Qmaster distributed processing system will automatically copy the appropriate media files to the processing cluster. For the best performance, you can avoid this file transfer step by making sure that the media files specified in the reference movie are available to each node of the Apple Qmaster cluster.