STOP:  Read this entire article before taking action and if you have any questions please open a support case. This process should ONLY be used IF you have a failed/damaged database and;

  • Do not have or do not want to take the time to restore from an earlier backup
  • Want to get users up and operational ASAP so they can continue sending/receiving email while recovering the historical data from a damaged database with DigiScope.


        NOTE: If you plan on restoring from an earlier backup, portions of this process can be used to preserve and then restore missing data from the damaged database 


PROS of the Dial-Tone Recovery

  • Fast, can be executed in a few minutes and mail begins to flow immediately
  • No need to create a new database and re-home users via active directory to the new database
  • DigiScope can restore messaging items from the damaged DB or a backup copy of the database while users are working within their mailboxes, i.e. they can send and receive new emails while the historical data is being restored by DigiScope during normal hours without further interruption to users.
  • When a damaged database is repaired using eseutil /P it not only takes a long time to complete the process can also remove valid data if it exists within page that has damage.  Furthermore, best practice demands that a repaired database be defragmented post repair, aka more time to complete.  Then as if that were not enough pain MS states you must create a new database and evacuate aka MOVE all users from the old damaged EDB into the new database and then destroy the old database. Yep even more time and resources.  This is because Microsoft will not support a database that has been repaired, read more about that here https://blogs.technet.microsoft.com/exchange/2015/05/01/new-support-policy-for-repaired-exchange-databases/ 


CONS of the Dial-Tone Recovery

  • Users will not have their historical email immediately, although the alternative is to have no email access for hours/days depending on the recovery time which can easily be hours, days, weeks depending upon the DB size, degree of damage and other variables. 
  • Account with caching enabled aka OST files will be inconvenienced since OST files contain an encryption key that must be matched to the mailbox within the Exchange database.  Since the dial-tone is a fresh database it does not have this encryption key information and there is no way to restore that information into the database.  Therefore those accounts will have a new OST after they connect to the new database and the old OST will be orphaned (unable to be opened) or deleted depending on the version of Outlook in use - more about that below.


Preserve the Damaged Database(s)

Before taking any action you need to ensure the damaged database(s) have been preserved by taking the following actions

  • Determine the Database .EDB and .LOG paths of the affected Exchange database
  • Rename the Database .EDB and LOG paths by prepending "OLD_" in front of them, for example; 
    • If the Database path is G:\Program Files\Microsoft\Exchange Server\V15\Mailbox\FABRIKAM-13 
      • Rename folder from FABRIKAM-13 to OLD_FABRIKAM-13
    • If the LOG path for the database is X:\Program Files\Microsoft\Exchange Server\V15\Mailbox\FABRIKAM-13_Logs
      • Rename folder from FABRIKAM-13_Logs to OLD_FABRIKAM-13_Logs

NOTE: if the EDB and LOG paths are the same then you will only have a single folder to rename                

NOTE: If the OS wont let you rename the folders where the EDB and LOGs reside you may have to stop the Exchange Search Services first.

  • Next recreate the previous database and log folder, i.e. in our example we would recreate the  FABRIKAM-13 & FABRIKAM-13_Logs folders
    • You should now have the original folder name and the renamed Database and Log folders in the same path, so using our example we now have the following
      • FABRIKAM-13 & OLD_FABRIKAM-13
      • FABRIKAM-13_Logs & OLD_FABRIKAM-13_Logs

                NOTE: if you stopped the Exchange Search services in order to rename the original folder be sure to restart the same services AFTER recreating the folders


Check Available Disk Space

Before proceeding its wise to ensure you have ample disk space on that drives the Database .EDB & .LOG files are located.  The amount of space needed will vary depending upon your organization, # of mailboxes, how long the database has been offline etc. Basically you want to have a reasonable amount of disk space available before creating the dial tone database.   


Create Dial-Tone Database

  • Open the Exchange Management Interface and depending upon the version of Exchange it will be referred to as the 
    •  Exchange Admin Center (EAC) for Exchange 2013/2016
    • Exchange Management Console (EMC) for Exchange 2007 & 2010
    • System Manager for Exchange 2003
  • Navigate to the section where you can mount/dismount databases
    • Right-Click the damaged database and select Mount
    • Exchange will respond with a message that will vary depending upon the version of Exchange however it will be something like "At least on of this store's database files is missing, Mounting will force the creation of an empty database......"
    • Confirm the action
    • A new database is created and all pending inbound email is delivered to the appropriate mailboxes


Validate Connectivity 

Open Outlook Web Access (OWA) and confirm that emails can be sent and received. 

NOTE: You may need to restart the web services on the Exchange Server to get OWA working again, however attempt access before taking this action


Outlook with Caching Enabled / OST Files

As stated above within the CONS of the Dial-Tone restore accounts that have caching enabled will be inconvenienced since there is a unique encryption key between each users profile that contains the OST and the associated Mailbox within an Exchange database. When users connect to their mailbox after the dial-tone dB is mounted they will be see a dialog (varying by exchange version) that will in short give them two options

  • Connect to the Server
    • This will orphan the old OST and create a new OST along with a new encryption key between the OST and the Mailbox
  • Work Offline
    • This allows the user to OPEN the offline OST file, however they will only see old data in the OST, not anything new in the server, nor can they send email
    • However, the benefits of opening the offline OST file BEFORE connecting to the new database are;
      • Once opened the user can EXPORT the entire OST into a PST format.  
      • This can be advantageous since the exported PST file does not have an encryption key and therefore the user can be online within their new mailbox and access to the historical messages within the PST file.


Restore Historic Information from Damaged Database

Now that you have the new dial-tone database in place and have confirmed email is flowing you need to restore the historical data within the offline damaged database.


  1. Unless you have allot of free disk space, i.e. enough to keep the old damaged database along with the new dial-tone db post restoration of all data you should move the OLD_Database and Log folders to another location so that you can free up space on the production server
  2. While its certainly possible to use DigiScope to open the original offline copy of the damaged database, best practice is to make a WORKING copy from the MASTER/ORIGINAL copy of the database
  3. Add a WORKING copy of the database to DigiScope Offline pane
    • Since the database is damaged we only want to open the database file, therefore, ensure their are no .LOGS within the database folder and DO NOT define the LOG path when adding the database to DigiScope
  4. Mount the database using the Mount/Forensic Mount option
    • If Forensic mount will not work you will need to execute an Offline Repair using DigiScope, but again this is ONLY if the Forensic Mount will not work and ONLY against a WORKING copy of the damaged database, NEVER the original/master copy
  5. Execute a Single Touch Restore

 


SUPPORT: If you experience issues, have questions or need assistance after following these instructions please Open a New Support Ticket or if you already have a ticket open reply with details and we will be happy to assist.