I have been doing some work on Exchange of late. We make liberal use of the Litigation hold feature and have all lagged copy of all our databases in our DAG. Today I am getting ready to apply an rollup to exchange. Prior to doing the rollup I noticed that a few of my databases are getting rather large due to the liberal use of the Litigation hold feature I mentioned. So the simple solution is to create more databases in the DAG and migrate some mailboxes and online archives to the new databases. Spread the load if you will.
So a few things to keep in mind when doing this process – If you have lagged copies of your databases you might want to make sure they can’t ever be activated. Because that would be very bad as you would lose the lag. In my case I lag for 7 days on my lagged copies. In the EMC, it will always show a Activation Preference even if you have blocked the activation so it’s always good to set this when adding a copy of your database.
Let’s take a look at adding a new database to the DAG:
Step 1: Create a new Database in your DAG (from EMC, under Organization Configuration -> Mailbox)
Step 2: Mount the database
Step 3: Right click and “Add Mailbox Database Copy” to add the copy to your other mailbox servers.
Step 4: Set your lag copy up. This is done via Powershell.
[ps] c:\ Set-MailboxDatabaseCopy -Identity DATABASENAME\SERVER -ReplayLagTime 7.00:00:00
Step 5: Block the activation so it can’t ever fail over to the lag copy unless you do it manually.
Again this must be done in Powershell (EMS)
[ps] c:\ Suspend-MailboxDatabaseCopy -Identity DATABASENAME\SERVER -ActivationOnly
When the cmdlet is run with the “-ActivationOnly” parameter, the database copy cannot be activated unless you do it manually. The command to allow it to be activated is:
[ps] c:\ Resume-MailboxDatabaseCopy -Identity DATABASENAME\SERVER
NOTE: You can run this command for every database on a server (if you have a server dedicated to hosting your lagged copies for example) This is done like this:
[ps] c:\ Set-MailboxServer -Identity SERVER -DatabaseCopyAutoActivationPolicy Blocked
To disable this set the -databasecopyautoactivationpolicy to “unrestricted”