We have a content source in a 2010 Fast Search site that has around 600,000 items to crawl. We have full crawls setup to run every Friday night as it usually takes us about 34 hours to run the full crawl. However, the full crawl on this same content source is still going from last week and is now only at 485,000 items after 92 hours, so at this rate it's going to take another 22 hours to complete. Previously we were seeing times of about 17,000 per hour, the current rate is about 5200 items, or about 1/3rd of the performance we usually see. On top of this, the processor has been pegged at 100% since Friday night. I don't see anything really standing out in the task manager that is eating resources, other than what appears to be the indexing processes. AV software doesn't seem to be the problem from what I can see. Memory is fine and only using 33%, machine was rebooted but didn't seem to impact the crawl rate we are seeing. Please let me know if you have any ideas on what may have degraded our performance or areas to check.
Thanks!