Quick Description: An existing, working installation of Office Search Server protecting a WSS farm stops updating the index and the crawl appears to be hung for an extended period of time.
Problem: When the crawl hangs, new items and documents added to the WSS farm will not show up in searches. The crawl never finishes.
I'm temporarily doing a bit more SharePoint administration, which includes the care and feeding of our old WSS 3.0 farm. It's not as exciting as the shiny new 2010 architecture, but it's our day to day workhorse and I'm learning little tips and tricks for coaxing WSS 3.0 into lasting until you can fully migrate to 2010.
In these cases, we've traditionally been told to rebuild the index. This fixes the problem, but effectively kills search for the time it takes to get items into the index. If you have a large farm like us, it could be several hours before you have all items indexed.
Solution: On the application running Office Search Server, go to Start, Programs, Office Search Server, Office Search Server Administration.
In the admin console go to crawling, and click content sources. Check the dates of the last crawl, and the duration of the current crawl. If the current crawl has been going for an unreasonably long amount of time, stop the crawl by right clicking on the content source and selecting stop crawl.
To start a full crawl without destroying the current index, select the content source, and on the Edit Content Source page, scroll to the bottom and check "start full crawl of this content source." The index will now rebuild without resetting and destroying the existing index.
If this doesn't solve the problem, you may need to reset all crawled content which will destroy the index. If you reset all crawled content, searches will not return results until the content being sought is crawled.