There are number of reasons that call for dismounting database from Exchange Server 2010; may be for Switch-over (scheduled outage), for hardware replacements, for repairing database etc. The process of dismounting and mounting DB is not at all complicated but can create trouble if database is inconsistent.
Just consider an example: After some maintenance tasks, when you tried to mount DB on Server but the process failed with error: Failed to Mount Database “Database Name”.
This inconvenient situation might have arisen because the mailbox or public store database that is being tried to mount on Server is inconsistent. To work around, first confirm the state of DB that is being tried to mount using Eseutil /mh switch.
Verify State of Exchange Database:
In Command Prompt, navigate to “Drive:\Program Files\Exchsrvr\Bin folder” (Drive indicates where Eseutil is installed). Enter the command for:
If the database is inconsistent, then state of database will be: DIRTY
Now, to get data from DB that is inconsistent, there are two available approaches: Either restore it from recent backup or repair it. Here is how you can mount Exchange 2010 mailbox when it is in dirty shutdown state:
- Replay Transaction Logs: When there is no backup but all log files are available, perform soft recovery. This will replay all transaction logs and will help to bring DB into clean shutdown state. For this, Syntax is:
“Eseutil /ml “Path of the log files\log prefix”
b. Restore from Online Backup: When EDB and LOG files restored from backup, a file named “Restore.env” will get generated in temporary folder in C:\ Drive. Now, using Command Prompt, perform hard recovery of database that will replay log files against restored DB. Use the syntax: ‘Eseutil /cc “Path of the restore.env containing folder’
c. Repair DB Using /p Switch: In case backup and log files are not available, the option is to repair the database using Eseutil /p switch. Use the syntax: Eseutil /p <database_name>
Note: Remember that this process involves removing corrupt pages from the EDB file and thus can cause some data loss.
Now, try to mount the database and if is it still un-mountable, it means there is some other reason behind the problem. You can also attempt the powershell commend for extracting data from corrupt Exchange Server 2010 Mailboxes. If these both method is not working that mean their is major issue happened. To get rid of trouble, download free Recovery tool that allows migrating mailboxes from EDB file to live Exchange Server. This solution has the quality to extract mailboxes from corrupt/inconsistent EDB files and export them to PST, EML, MSG files or to another Exchange Server.