A few days ago my server became very slowly without reasons.When i open the PHP log file on c:\windows\temp ,
Suddenly ... stuck!

Decisively disable the Php error log.But does not solve the problem.Suddenly found a large number of files beginning with sess_ on the temp folder.The number has reached 100,000! Although only a total capacity of 300MB, but the space has reached 3G.It seems that the problem lies here!

Delete these files is required,but the process is very painful ... because the system stuck.At last use the del *.* /q /s to delete all the files.

In fact, these files are PHP saved session file.A Session corresponds to a file, but when the end of the Session should be deleted.Why did not remove it?In fact, PHP will be deleted, but due to permission issues, which led to it can not delete a timely manner.Just need to add the delete permissions to IIS_USERS .Now there are no to many sess_ fils.The server becomes normally.

This address is http://www.computerites.com/web-design-skills/2013/04/temp-folder-permissions-problem-causes-site-failure-in-iis-php-environment-731.html