Jan 23 2018 04:08 AM - edited Jan 24 2018 12:02 AM
I have a quick question regarding the “Exchange Server Role Requirements Calculator”.
I have a medium sized Exchange 2010 Environment that I would like to upgrade to Exchange 2016.
The current Exchange 2010 design is based on an Active/Passive design with a Single DAG that is shared across the 7 Mailbox servers. We have around 5500 mailboxes spread across 10 databases.
When I came to put all this detail into the “Exchange Server Role Requirements Calculator” it suggested I have
• 6 Servers in Active site
• 3 Servers in Passive site
I agree with the server design but were a bit surprised when it suggested I have 9 Database Availability Groups? Is this correct? Why can’t I have just one DAG like in my Exchange 2010 environment?
In the attachments:-
You can force the Calculator to use 1 DAG but then it blows the server configuration
Jan 24 2018 12:48 AM
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
Jan 24 2018 01:52 AM
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
Jan 25 2018 12:06 AM
Adding @VasilMichev and @TonyRedmond @Ross Smith IV to review your calculation
Jan 25 2018 02:33 AM - edited Jan 25 2018 02:34 AM
SolutionFinally, 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 🙂
Jan 25 2018 02:48 AM
Thanks for sharing your findings. That shows how important is your SPECINT value.
are you hosting it on Physical Machines or on VM Platform?
Jan 25 2018 02:57 AM - edited Jan 25 2018 03:00 AM
VMWare Platform
Thank you for helping me get to the bottom if the issue 😉
Jan 25 2018 03:56 AM
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.
Jan 25 2018 02:33 AM - edited Jan 25 2018 02:34 AM
SolutionFinally, 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 🙂