On a recent SharePoint 2013 deployment, I faced a strange issue, wherein the search index got corrupted and I was not able to reset the index. Although, I was able to get to the reset index screen and the reset index button was clickable, but each time it went into an infinite loop on clicking the reset index button, and the index was not reset.
After much banging our heads and googling around, I found a small piece of information that really helped and did the trick. Below is a step-wise approach to resolve such an issue.
Stop the Windows SharePoint Services Timer service
Navigate to the cache folder in the following location: System Drive:ProgramDataMicrosoftSharePointConfig
Locate the folder that has the file “Cache.ini”. There may be multiple GUID folders with cache.ini file
Back up these folders with the Cache.ini file
Delete all the XML configuration files in the GUID folder
Note: When you delete the xml files within the GUID folders, make sure that you do not delete the GUID folder and the Cache.ini file that is located in the GUID folder
Open the Cache.ini file and delete the content, replacing all the text with the number ’1′. Save the file and close
Start the Windows SharePoint Services Timer service
After the above steps have been executed, make sure that the Cache.ini file contains some other value and not 1