Unable to Mount Database

By Joseph Piggee Sr.
Symptom:
MapiExceptionCallFailed: Unable to mount database
First check the status of your database and if necessary do a soft recovery using eseutil:
1. Open your EMS
2. Type eseutil /mh "C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database\[b]Mailbox Database.edb[/b]" (Change the edb to the name of your database)
3. Look for State: Dirty Shutdown
If you do have State: Dirty Shutdown
1. You will need to repair the database by typing the following command:
eseutil /p "C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database\Mailbox Database.edb" (Change Mailbox Database.edb to the name of your database)
2. Re-run the database check:
Type eseutil /mh "C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database\Mailbox Database.edb"
3. Check for State: Clean Shutdown
4. If clean, try to mount your database, and you should be good.

Another way to fix:

Check and Repair the database
1. Check the database:
eseutil /mh "C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database\Mailbox Database.edb"
Look for the following in the output: State: Dirty Shutdown
1.a Since the database has not been properly shut down, it needs to be repaired.
Make sure you make a backup of the database before attemting any kind of repairs
To repair, run the following:
eseutil /p "C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database\Mailbox Database.edb"
1.b Re-run the database check from 1.a and if all goes well, you should see this somewhere in the output: State: Clean Shutdown

You can try mounting the database. If it mounts, you are good to go, if it doesn't you have to check the logs:
Check and Repair the database logs
2. Check the exchange logs (don't forget to specify E00 - the starting sequence for the logs)
eseutil /ml "C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database\E00"
2.a There will be a list of logs and depending on their state, you may get an error. (They should all say OK, if the logs are clean) Errors vary, but most likely it is a file corruption and needs a chkdsk to run.
As a sidenote, if the database state is Clean Shutdown you can safely remove the logs.