FAST Search index servers out of disk space after or during a crawl

Gilt für: SharePoint Server 2010


When adding new content to the FAST Search backend, you find that the %FASTSEARCH%\data\data_index size has expanded to all available disk space, and your crawled content may not be fully searchable or indexed.


FAST Search Server keeps a read-only binary index file set to serve queries while building the next index file set. The worst-case disk space usage for index data is approximately 2.5 times the size of a single index file set. There may not be enough space on the current storage solution for indexing to complete.


If additional storage can be added to the server, the entire %FASTSEARCH%\data directory can be moved to a new location with the same permissions ("Full Control", granted to the FASTSearchAdministrators local group), and connected back to the installation via a junction point. To do so, follow the steps below on each FAST index server:
  1. Stop the FAST Search for SharePoint service.
  2. Stop the FAST Search for SharePoint Monitoring service.
  3. Move %FASTSEARCH%\data to the larger storage you have added.
  4. Run the following in a command prompt: mklink /j %FASTSEARCH%\data %NEW_LOCATION%\data
  5. Start the FAST Search for SharePoint Service.
Please note that while other methods of relocating the index outside of the %FASTSEARCH% parent directory are not supported, the entire partent directory can also be moved to a new physical location without using a junction point (skipping step #4 above) if the drive letter, path, and permissions remain identical.

More Information

If the data_index directory has many incomplete index directories within each numeric subdirectory (e.g. in the "2" directory), you may choose to force a clean rebuild, to have a better idea of the storage requirements going forward and to ensure that space remains available. To do this, before starting FAST Search in step #5 above, delete the data_index directory. Then, start the FAST Search service, and indexing will pick up all previously crawled content stored in data_fixml.

Please note that it is not supported to have separate junction points data_fixml and data_index on an indexer-node instead of %FASTSEARCH%\data.