There can be several kinds of failures during filtering, indexing, and merging. Except after a hardware failure, indexes are fully recoverable. Indexing and merging are temporarily paused if the system's memory load is very high. Failed operations are retried later.
A merge is not started if the free disk space is very low on the catalog drive. However, it is possible that the drive may run out of free space while the merge is happening. A shadow merge will be aborted and retried after disk space is freed up. A master merge is not ended but temporarily paused. An event is written to the Windows NT event log that the Master Merge is paused. A disk-full event will also be written. The administrator should free up disk space by moving or deleting unneeded data files from the corpus.
Important Do not delete any files under the Index Server Catalog Directory.
The system will automatically detect when enough disk space has been freed and will restart the operations.