Upgrading 2003 R2 x64 server to 2008 R2 - clean install or Upgrade

[timbo343]

Just want peoples views on this...

I have got 3x dc's left on 2003 R2 x64 at the mo and im unsure if i should do a clean install or upgrade. I know about decommissing them before doing the upgrade, moving the fsmos and i have already run adprep for domain, forest and gp levels and i have just made a 2008 r2 machine a temp DC just incase.

Now, 2 of the DCs in question are DNS's. Would an upgrade run smoothly or would i have to move the DNS's for a day while the upgrade takes place? 1 of them runs Backup exec 12 so that will have to be removed and new backup software will have to be considered (which i am open to all options) and also MLS eclipse (which again needs backing up before i do anything and will need SQL express 2008 installing in the end).

Can anyone offer any advice?

Tim

[teejay]

Clean install all the way, I would never do an OS upgrade on a server unless I really had to, especially DC's. Don't flatten them all at the same time, for the DC's and DNS take one down, install OS, add AD and DNS roles and it will replicate off your existing AD and DNS. DHCP can be a bit of fun, if you haven't got a complicated setup then its easier just to start from scratch. Leave at least 24hrs before taking down your final DC to make sure everything has fully replicated across.
MLS will move across ok, just make sure you're on the latest version first.

[bio]

fully agree with teejay here

bio..

[john]

Clean install one by one to make sure all is good and happy and you will be fine

[strawberry]

and for your backup i suggest dpm from microsoft, much cheaper than backup exec.

[FN-GM]

I think you will have to do a clean install anyway as i dont the upgrade option is available form a server 2003 machine

[oxide54]

and for your backup i suggest dpm from microsoft, much cheaper than backup exec.

and if your on schools agreement , your agents get upgraded with the OS / Exchange / SQL

it can be a pain when you reliase you have to pay £££££ to upgrade your backup software before you can upgrade your exchange server.

[Firefox]

Can't remember if upgrading was an option...but we chose to carry out a clean install. All went seemlessly.

Migrating the DHCP scope is a nice simple command line, DNS was easy enough to transfer off.

Are you going to be thinking about putting in a KMS server? will make managing the licenses for your new servers a lot easier.