Forum Discussion
Exchange Server Role Requirements Calculator: DAGs required
Finally, I think I know what the problem is - My SPECINT2006 value was way off - I downloaded this tool "Exchange Processor Query Tool" https://gallery.technet.microsoft.com/Exchange-Processor-Query-b06748a5 and it calculated my SPECINT2006 value to be 645. Now the Calculator works correctly and recommends 1 DAG :-)
The calculator also assumes you are calculating for 4 copies of DB and you should check the second tab to see the calculation which it did. also the database copy layout tab
Here are the values. I understand that you would have 4x Database Copies per server - That is correct and there are 3 copies of a Database instance replicated - Two on the Primary Datacenter and One on the DR Datacenter.
But where do the 324 copies come from? I know that 9 x 36 = 324 - But that suggests I have 9 DAGs
Surely then the Database Copy Instance Configuration values should be multiplied by 9...?
I still don't get how the Calculator can recommend I use 9 DAGs?
Database Copy Configuration
Number of Database Copies
/ Server = 4
/ DAG = 36
/ Environment = 324
Database Copy Instance Configuration
Number of HA Database Copy Instances / DAG
/ Primary Datacenter = 2
/ Secondary Datacenter = 1
Total = 3
Adding VasilMichev and TonyRedmond Ross Smith IV to review your calculation
Finally, I think I know what the problem is - My SPECINT2006 value was way off - I downloaded this tool "Exchange Processor Query Tool" https://gallery.technet.microsoft.com/Exchange-Processor-Query-b06748a5 and it calculated my SPECINT2006 value to be 645. Now the Calculator works correctly and recommends 1 DAG :-)
Just be aware that the current calculator takes no account of the mitigations released for the Meltdown/Spectre vulnerabilities. Some impact is to be expected in most Exchange environments, but you will only be able to confirm the exact effect on performance by running a test load.
