Purge is used to delete recordings that are no longer worth storing. These purged recordings are deleted.
Each camera specifies how many days to keep its recordings, up to (an unrealistic) 10 years. Not all cameras need to record. For those that do, a purge is needed to keep disk storage available for new recordings. The purge checks each camera's default recording base path, as well as the camera's current user-specified recording base path (if any has been specified).
Purge runs once daily, at a prescribed time. This is by default at 23:45 (11:45pm). This purge-at time can be from 00:01 to 23:45. You can also initiate a purge at any time by pressing the Now button (there is a built-in 2-minute delay after a purge completes before another purge can start; this is significant for early purges).
In addition to the standard, days-to-keep purge, a purge may run based on available drive space, either as a percentage of total drive space or absolute drive space (in GB).
For example, if Early purge % is set to 10% (it can be no more than 50%) and Early purge GB is set to 67 GB (it can be no more than 500 GB) then every two minutes CAMNET server checks the available space on all recording drives (it does this only if either Early purge field has a non-zero value). Those drives which fall below the Early purge setting become eligible for early purging. It is okay for both Early purge % and GB to be set to 0, for one to be set to 0, or neither. If no Early purge is specified, only the days-to-keep for each camera is used as the basis for purging.
Early purge works in stages. At first, when a drive becomes eligible for early purging, the purge still honors the original days-to-keep value. If a recording is older than that period, it is deleted, and the space it used is freed. If, at the next stage 2 minutes later, the drive still falls below the Early purge setting(s), the process repeats, but this time, each camera's days-to-keep value is reduced by a day (from say, 40 days to 39 days). If recordings now are found older than that, they are deleted and the drive space becomes available. This process continues (if needed) until there is 1 day left of recordings (today's and yesterday's) at which point no more purging can be done.
If you change the Purge at time, or change the Early purge % or GB value when both were 0, press the Now button to signal the purge to wake up. The purge action normally sleeps 24 hours between jobs if there is no early purge to check. Press Now to wake it up and to set up the new purge-at time, or early purge values right away.