XADM: .Pat Files in Mdbdata and Dsadata Directories

MORE INFORMATION

Patch files (.pat files) are created when doing an online backup of the Exchange databases. These temporary files get created as soon as the backup process begins; they contain whatever transactions take place during the online backup. This way the Edb.log can be copied during the backup while transactions are written to the patch files. The *.pat files are also copied to the hard disk drive and replayed when a restore is done.

It is safe to delete these patch files if these two conditions apply:

• There is no backup taking place.
  
  
• There is no startup recovery in process after a restore.