SharePoint: Maximum File Size for Crawling Search Services

Maximum File Size for Crawling Search Services
By default, Search Services can crawl and filter a file with a size of up to 16 megabytes (MB). It will always crawl the first 16MB of a file. After this limit is reached, SharePoint Portal Server enters a warning in the gatherer log “The file reached the maximum download limit. Check that the full text of the document can be meaningfully crawled.” To increase the limit of 16 MB, you must add in the registry new entry MaxDownloadSize. To do this, follow these steps:
Start Registry Editor (Regedit.exe).
Locate the following key in the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office Server\12.0\Search\Global\Gathering Manager
Open Edit - New - DWORD Value. Name it MaxDownloadSize.
Double-click, change the value to Decimal, and type the maximum size (in MB) for files that the gatherer downloads.
Restart the server.
Start Full Crawl.NOTE: Increasing the file size may cause a timeout exception because the crawler can timeout if the file takes too long to crawl/index (because of its size). To increase timeout value, follow these steps...for the full post, check out Maximum File Size for Crawling You can also review searcu usage data by enable search query logging by following these steps:
On the home page, on the Site Actions menu, point to Site Settings, and then clickModify All Site Settings.
On the Site Settings page, under Site Collection Administration, click Site collection usage reports.
On the Site Collection Usage Summary page, on the Quick Launch, click Search queries or Search results.Additional resources: