The system purges partitions based on disk space, time, or the maximum number of allowed partitions.
When purging based on disk space, a purging algorithm considers the overall amount of free disk space. For example, three 100 GB volumes exist, each with 30 GB of free space, giving you a total of 90 GB of free space and a total disk space of 300 GB. The total event data size is the sum of index sizes on all three volumes. (This could be less than 210 GB since the main data volume can also contain store files and other data.)
The following shows how the current purging thresholds (in cb.conf ) are interpreted when multiple volumes exist:
MaxEventStoreSizeInPercent- Purge the oldest partition when the total sum of all event core sizes exceeds the given percentage of a total disk space (on all volumes).
MaxEventStoreSizeInMB- Purge the oldest partition when the total event store size (on all volumes) exceeds the given threshold.
MinAvailableSizeInMB- Purge the oldest partition when the total free disk space (on all volumes) falls below the given threshold.