Virtualization vs High Availability

So last month I had a meeting with IT staff and the GM, apparently the GM thinks that Virtualization means no need to have multiple server with same role. "I use virtualization so we can just restore the server using snapshots in case of server going down", it sound correct, but it won't change the most basic problem, downtime.

We have Virtualization so we can deploy server and use resource more efficient than having physical servers. But high availability requires planning and multiple server with the same role(a failover or load sharing group). Virtualization allows you to clone the server or restore from snapshots when hell break loose, but it will cause downtime(and non-stop angry phone calls). High Availability (with good planning and best practice) allows you to have 1 or more server down and let you fix them without angry phone calls. Your colleague will never know that the server had problem, from their point of view, everything works fine even when you took down a server for maintenance.

When your company is small enough(and doesn't need fancy or high availability server), having all server running on 1 host (each without high availability) is still ok, all you need is regular backup(preferably daily and hourly for database). But when the data becomes really important, it's time to think about high availability and disaster recovery. Sadly my boss is still unconvinced, 1 server for each role is enough, having a server with multiple role is good(yes except when the server is running database... like exchange server). Seems like I need God's help to strike the server down and let him know that high availability is God's gift to mortal...

Exchange 2010 to 2013

So today I tried to install Exchange 2013 and do coexistence with Exchange 2010,
1. Install SP3........ done!
2. Install RU6....... done!
3. Install Exchange 2013.... fail!?!?!?

Apparently Exchange 2013 thinks that the other Exchange Server is still 2010 SP1..
I tried to reinstall the SP3... but it's already on RU6, so I tried to reinstall the RU6, still won't do...
After googling around and messing around, I found out that the Exchange installer failed to update the AD configuration, the system configuration still showing 14.1.x which is SP1, damn now I found the problem.

2 days later, I still can't find the solution, registry says the correct version, technet shows nothing, apparently some people in internet face the same problem with no solution...
No choice but messing around with ADSI, first I found out that serialNumber and msExchVersion relates to the version Exchange Management Console version showing, changing the entry was easy, but it still won't solve the problem. So I tried to use all my Google jutsu... until I found 1 (yes, only 1) website which have more or less the same problem(he use 2007 instead of 2010). Apparently, serialNumber does nothing other than cosmetic purpose, Exchange use binary format for version detail which saved under the name of versionNumber, this website told the other guy how to fix it. When faced with 2010 SP3 error on Exchange 2013, all you need to do is make sure that you really have SP3, then do this

open ADSI, then expand CN=Configuration], CN=Services, CN= Microsoft Exchange, CN=[ExchangeDomain], CN=Administrative Groups, CN=Exchange Administrative Group (FYD...), CN=Servers, CN=[Your Exchange Server]
right click and shows properties, find the versionNumber then change the number into
1937998019 if you use Exchange 2010 SP3 RU6
1912832298 if you use Exchange 2007 SP3 RU10
you can also fix the version number for cosmetic purpose :D

After that you can go back to other server to install Exchange 2013 and start migrating!

Now I need to get back for ASE exam...

Credit: http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Server/Windows_Server_2012/Q_28144192.html
http://blogs.msdn.com/b/pcreehan/archive/2009/09/21/parsing-serverversion-when-an-int-is-really-5-ints.aspx