I'm setting up some new Windows 2012 servers to replace old ones currently on 2003. One of my concerns is to try and have a suitable DR plan to get them back up and running if we have a major failure. I plan to have the following:
Server 1: Domain Controller, File/Print server, SQL Server, Web Server
Server 2: Exchange (2013) Server
Server 3: "Backup" Domain Controller
I will also have spare server hardware (identical) to be used in case of failure.
My main issue is around the backup of Server 1. Firstly, just to say there will be a maximum of 100 users and the file/print and SQL will probably only be used by about 25. I know in a totally ideal situation the DC would be that and nothing else but this is a relatively small setup so I don't see a problem with having all those services on one box.
In an ideal world I'd like to run a disc clone and then have that available to restore in case of total server failure (followed by then applying backups of database, user files etc). However as I understand it you should never restore a clone of a domain controller as then all the numbering is out of sync and replication will fail etc.
I thought of prepping the server but taking a clone just before promoting it to a DC. However reading the notes on SQL Server (I will be using Express 2012) it says that while it will run on a domain controller you can not promote (or demote) the server while it is installed. I.e. I can't install SQL and then promote the server.
So it seems currently my DR plan would have to be restoring a Win2012 clone and then rejoining it to the domain, promoting it, reinstall SQL etc i.e. quite a lot of steps.
One thought I had is if I did go against the rules and cloned the whole system, then in case of failure could I do a full restore but then immediately remove the "backup" domain controller from the domain (and later reintroduce it) (to get the replication numbering back in sync)? That would I assume have lost any AD changes since last backup but given the size of our organisation they are likely to be minimal.
Any other thoughts welcome.
Best Answer
Have you considered using VMs instead of trying to stuff everything on the hardware ? That would make your system easier to backup and manage. You might need a couple of additional windows server licenses but not only will you get around the issue of having multiple services running on the same OS but you'll also gain the ability spread the load more efficiently between physical machines.
It will also make DR much easier assuming you have a good backup policy.