Your current index size is 700 GB and your available disk space is 1293.14 GB for the D:\RetainStore\index path. While you may have enough disk space for now to continue indexing message content, you may not have enough disk space to perform the recommended weekly maintenance on your indexes. During the course of indexing, new segments are created. By default (configurable), on a weekly basis the nightly maintenance will spawn the indexer process optimize your indexes by merging those new segments into a single segment. While this is occurring, it could require free disk space up to twice the current size of your indexes. We recommend adding more disk space to at least provide double the current size of your indexes as available disk space so that Retain can continue to optimize your indexes. If you keep your indexes on the same volume as your archive files, then you'll also want to consider for future growth of the archives as well. If it cannot run the maintenance on the indexes, this can adversely affect the performance of your searches in Retain.
This warning occurs when the volume, or partition that the index is on, does not have enough disk space in order to migrate the indexes, if just upgraded from a previous version of Retain, or there is not enough disk space to optimize the indexes.
When optimizing the indexes, the indexer will make a copy of the indexes, increasing the disk space 2 times the size it is currently. If archive jobs are running, the indexes will be tripled. As a rule of thumb, in order to prevent the warnings and notifications from appearing, it is best to have at least 3x the space of the current index size.
To stop the warning do one of the following:
1. 1. Increase the size of the index partition to 3x the size it is currently. Use the warning message to assist in the calculation. For example 700 GB x 3 = 2100 GB.
a. Check the size of the indexes on disk.
b. Multiply the size of the indexes by 3.
c. Increase the disk size accordingly.
2. 2. Reduce disk space. This KB article can help reduce old indexes from older versions of Retain: