How to troubleshoot database cannot mount issue?
1. If all stores are unable to mount, please check if the following services is started first: Microsoft Exchange Information Store Microsoft Exchange System Attendant Then check if you run a File-Based Antivirus Software scanning against the program and database files of an Exchange computer. Please disable the anti-virus software and test the issue again. In order to isolate the issue, you can also create a new database to see if it can be mounted. 2. If one specific is unable to mount, please first check if you are running Exchange Standard Edition, your mailbox stores will dismount when you reach the 16-GB size limit, KB 828070 addresses this issue. According to KB 314917, check if there is -1018 or -1022 error in the application log indicating a problem with your physical storage. Verify that the database was shut down in a clean (consistent) state. Use ESEUTIL /MH. If the database is shutdown in a dirty (inconsistent) state, you cannot mount it and you must replay at least one tr
