Scheduler and activity periods
The two main features of CodeTwo Backup - backing up and restoring data - are realized via the so-called jobs. A job, once configured, can be executed either manually or automatically, via a built-in scheduling capability. In both cases the principle of operation is the same, the only difference lies in the job execution type. However, jobs can also be divided according to their continuity: CodeTwo Backup supports one-time backup or restore jobs and continuous incremental backup jobs. A complete backup or restore operation is called a cycle and the time when a job is supposed to run is referred to as an activity period.
When a one-time job is started, it performs one cycle of a defined task (either backup or restore) and stops when finished. If you stop such a job manually during its operation, the next time this particular job is started again the software will rescan the source data and the content that is already backed up (or restored, depending on the job type), to compare them both and perform the defined task on modified items again (Fig. 1.). Unchanged items that are already backed up/restored will not be processed again - the software will resume the job where it finished before, backing up/restoring only modified items or items that have not been backed up/restored yet.
|Fig. 1. Backing up items after a job is stopped and started again.|
Continuous jobs run in multiple cycles and are limited to backup tasks. All backup jobs in CodeTwo Backup are incremental, which means they can be performed many times on the same mailbox: the program, recognizes changes in the already backed up items and backs up those changes again, each time a job finds one. Continuous jobs differ from one-time jobs in terms of what happens when the cycle is finished - they give users the ability to have their mailboxes scanned constantly. In this type of job, when the software finishes backing up a mailbox, it pauses for a user-defined period (called idle time) and then rescans the mailbox for changes, starting a new job cycle. If any changes or new items are found, the job backs them up. If this kind of job is manually stopped, once restarted it will proceed in a similar manner as a one-time job, i.e. only new or changed items will be backed up again (the software will resume the job from where it was stopped).
As mentioned earlier in this article, jobs can be run automatically using the built-in scheduling feature. The scheduler works in a similar manner to a Windows Scheduler, allowing an admin to plan and execute a desired job, without the need for constant supervision. When configuring the scheduler, a user defines the so-called activity periods which can be considered time slots for jobs (Fig. 2.). When an activity period starts, the scheduler executes an associated job. When this activity period is over, the scheduler force-stops the job, even if the job is still in the middle of a cycle. Jobs that were stopped before they actually finished will resume in the next activity period (if more than one were defined). Resumed jobs will proceed in exactly the same way as if they were stopped and restarted manually by the user. Keep in mind that the activity of jobs managed by the scheduler can be always overriden by the user - you can stop a job that is currently executed by the scheduler or you can start a job outside a defined activity period.
|Fig. 2. Running multiple job cycles.|
Scheduling backup jobs - this section describes how to enable and configure each activity pattern in the scheduler.