Exchange 2013 dial tone database recovery

In order to check if the database is in a healthy state we can use the command below, but first we need to be on the same location of the EDB file using either Exchange Management Shell
eseutil /mh

Use the eseutil utility in recovery mode (/r) to bring the database to a clean shutdown
eseutil /r


Use the New-MailboxDatabase cmdlet to create a dial tone database, as shown in this example
New-MailboxDatabase -Name DTDB1 -EdbFilePath D:\DialTone\DTDB1.EDB

Use the Set-Mailbox cmdlet to rehome the user mailboxes hosted on the database being recovered, as shown in this example
Get-Mailbox -Database DB1 | Set-Mailbox -Database DTDB1

Use the Mount-Database cmdlet to mount the database so client computers can access the database and send and receive messages, as shown in this example
Mount-Database -Identity DTDB1

Create a recovery database (RDB) and copy the database and log files containing the data you want to recover into the RDB. Rename edb file name to RDB.edb
New-MailboxDatabase –Recovery –Name  -Server name>  -EDBFilePath ‘X:\folder\RDB.edb’ –LogFolderPath ‘X:\folder\’

Mount the RDB, and then use the Dismount-Database cmdlet to dismount it, as shown in this example.
Mount-Database -Identity RDB1
Dismount-Database -Identity RDB1

After the RDB is dismounted, move the RDB database and log files within the RDB folder to a safe location. This is done in preparation for swapping the recovered database with the dial tone database.
Dismount the dial tone database, as shown in this example. Note that your end users will experience an interruption in service when you dismount this database.
Dismount-Database -Identity DTDB1

Remember about renaming edb file names!

https://technet.microsoft.com/en-us/library/dd979810%28v=exchg.150%29.aspx