With the latest release of Mailbox Server Role Requirements Calculator Microsooft develivered a tool to help you lay out your database copies correctly.
"On the Input worksheet, within the Database Configuration table, you can now have a new option, "Calculate Number of Unique Databases / DAG for Symmetrical Distribution". When this option is enabled, the calculator will use the permutation formula discussed in our guidance to deploy the correct number of databases based on the number of copies and server architecture such that you can potentially achieve a symmetrical distribution after a failure event."
"The calculator includes a new worksheet, Distribution. Within the Distribution worksheet, you will find the layout we recommend based on the database copy layout principles."
Important: The database copy layout the tool provides assumes that each server and its associated database copies are isolated from each other server/copies. It's important to take into account failure domain aspects when planning your database copy layout architecture so that you can avoid having multiple copy failures for the same database.
The Distribution worksheet includes several new options to help you with designing and deploying your database copies:
- You can determine what the active copy distribution will be like as server failures occur within your environment.
- You can export a set of CSV and PowerShell scripts that perform the following actions:
- Diskpart.ps1 (uses Servers.csv) - Formats the physical disks, and mounts them as mount points under an anchor directory on each server.
- CreateMBDatabases.ps1 (uses MailboxDatabases.csv) - Creates the mailbox database copies with activation preference value of 1.
- CreateMBDatabaseCopies.ps1 (uses MailboxDatabaseCopies.csv) - Creates the mailbox database copies with the appropriate activation preference values across the server infrastructure.
Downloa the new version of the calculator here.
[Source: Exchange Team Blog]