Do we follow the standard (5% of content IIRC) sizing metrics for Crawl DBs when using FAST as our search server, within our Content SSA; or are there separate metrics for FAST (ie. is the crawl controlled with the FAST admin service or the Content SSA.)

2 Answers 2


Sizing estimates are different

See the Planning and Architecture for FAST document on Microsoft's site

50 GB initial available disk space. As a general guideline, local attached storage is recommended for most deployments unless you have very specific deployment goals. Vital parts of FAST Search Server 2010 for SharePoint services are disk/IO bound, and will have limited access to SAN-specific storage sharing or caching.

Plan for 1 TB disk space per 5 million indexed documents. The actual disk usage is, however, highly dependent of the average size of the items and the selected feature set. Hence, it is recommended to perform a benchmarking for installations exceeding 10 million documents in order to install optimal amount of disk storage

  • Thanks. However, I am aware of course that for the index itself this is the case, however I'm thinking particularly of the Crawl DB created by the Content SSA - NOT the file based index itself. Any ideas; I'm sure it still creates the Crawl DB; but whether all the meta data is stored here, or it is passed off to the FAST data store I'm not sure? Thanks. Jan 8, 2011 at 17:30
  • Apologies, I failed to understand that was what you were looking for. If you look at Microsoft's sizing guidance there are separate sections for SharePoint search databases and the FAST ones. - technet.microsoft.com/en-us/library/cc678868.aspx#Section2 - technet.microsoft.com/en-us/library/cc678868.aspx#Section5 The guidance for FAST ignores the crawl db suggesting identical guidance, and available planning documentation certainly indicates it can get quite large. microsoft.com/downloads/en/… Jan 8, 2011 at 22:24
  • Arg that didn't display very well. The FAST crawl db stores data, and it can grow quite large. The last hyperlink provides evidence to that effect. Jan 8, 2011 at 22:26
  • Thanks for that. From that I'm going with the assumption that we stay with the original plan to size at 5% as with other scenarios. It makes sense as the Crawl DB and Prop DB are properties of the Content SSA rather than FAST itself, and this is used for both FAST and Enterprise Search. Cheers. Jan 10, 2011 at 10:38

The crawl db scales better for FS4SP compared to the internal search. It is used, but it stores less information so it can hold more than the recommended 25 million items per database. There are no official numbers on how much it can hold yet, but check this thread on the FS4SP forum.

This leads me to think you can probably count 2-3% instead of 5%.

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