My exchange 2016 has two databases listed. One is showing as healthy and the other is dismounted.

I suspect the dismounted one is the remains of a disaster recovery earlier in the year.

I want to remove the dismounted one, but worried it may break things.

If I remove it, and it proves it was required, can i re-attach it? Or is it a case of once it’s gone, it’s gone for good?


  • 1. Make sure you have a backup of the dismounted databases and log files. 2. If it's dismounted than it can't be in use, so removing it is unlikely to do any harm.
    – joeqwerty
    May 7, 2020 at 13:20
  • Hi, it's been a long time, is there any update? If the issue has been fixed, you could mark the best answer to help more people who have the same problem. Have a good day:)
    – Ivan_Wang
    May 19, 2020 at 6:26

2 Answers 2


Please keep in mind some important points:

  1. Perform a full backup of EDB file, before using Eseutil command.
  2. It cannot repair severely corrupted database.
  3. There should be atleast 20%-40% free space more than the size of the damaged Exchange database.

Also check when & how to use Eseutil from following links:




Are there any important mailboxes(Just like the manager's mailbox, Arbitration Mailbox etc.) still locating on the corrupted database? If so, to avoid losing the data of these mailboxes, you need migrate these mailboxes to another database. Besides, if the dismounted database is in corrupted, you could try to restore this database via ESEUtil(How to use ESEUtil tool):

  1. Run the Command Prompt, then switch the path with the command cd "Your corrupted Exchange Database path": enter image description here

  2. Run the command eseutil /mh "The edb file of the corrupted database" to check the Log Required(The value represents the lost log in the database) and the "State": enter image description here enter image description here

  3. If the values Log Required and State are similar with the above snapshot, you could refer to the part Repair your database with ESEUTIL(Soft Recovery using ESEUTIL) in the above link to repair your database.
  4. After the recovery completed and the State turned to Clean Shutdown, you could mount your database.
  5. Finally, according to your requirement, you could migrate all the mailboxes from the corrupted database to another one, then remove the corrupted database.

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