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Scheduler Preferences |
Check the Start and run actions while logged out setting if you want the scheduler to run actions when you are not logged in.
Checking this option installs the scheduler process as a background agent that continues to run even after you log out.
If this option is not checked, the QRecall scheduler process is only active while you are logged in. Technically, the scheduler runs as a user agent. If you log out, all QRecall actions are stopped, along with the scheduler.
Note: there is an issue with OS X 10.10 and later wherein the background daemon will not start running until you log in for the first time. This means that if you power up your system, but never log in, QRecall actions will not run as scheduled.
Actions that use an archive on an external, removable, or remote volume will attempt to automatically mount that volume when the action starts.
Check the Unmount volumes mounted by actions setting to unmount the volume again after the last action with an archive on that volume has finished. Volumes that were already mounted when the first action ran are not affected.
If other software is using the files on the volume when the scheduler tries to unmount it, the volume will remain mounted.
Letting two or more actions access different archives on a single magnetic storage device can significantly reduce performance due to a phenomenon called trashing. A drive that is being "thrashed" spends most of its time jumping back and forth between the requests from competing processes, and very little time actually reading and writing data. This results in two actions taking several times longer to complete than if they had been performed sequentially.
Similarly, your system has limited RAM and CPU resources. Letting an unfettered number of actions run simultaneously can saturate those resources, dramatically reducing the usability of your system.
The Maximum concurrent actions setting puts a limit on how many actions the scheduler will start concurrently. Setting this to Automatic sets a limit based on the amount of physical RAM and the number of CPU cores available.
The Maximum actions per volume setting constrains the number of concurrent actions that all use the same physical storage device (that is, two archives that are stored on the same volume, or on different volumes of the same physical drive). If you are using traditional magnetic storage devices, the recommended setting is Automatic or 1.
The concurrency limits only apply to actions started by the scheduler.
Actions started by any other means (manually starting an action, using the command line tool, and so on) run when you tell them too, even if that means they will compete with other running actions.
Note: If the scheduler is holding an action—waiting for other actions to finish—you can override the scheduler and force the action to start running immediately using the command in the Activity Monitor window.