We're still not ready to support sql 2008 (Company Infrastructure, vendors and DBA Group are a little slow), maybe this June or July we'll do the first sql 2008 implementation).
For me, most SQL Server migrations have been easy. No mess, no fuss, hit the "easy button". We even do the migrations the "hard" way...new servers, named instance, usually to a new clustered or consolidated environment using Polyserve or VM, and we separate all DTS (ssis) and User jobs out to an application (ETL) server. As a DBA with 100's of servers it's a lot easier to let each application group manage their own jobs, off the sql server, than for us to handle the requests. Usually the most difficult issue is connectivity, firewall and connection strings. Of 170 instances we support very rarely is there a difficult issue, we've dealt with some odd performance issues here and there, but for the most part it's been smooth sailing (hah, I remember being up for several days straight monitoring a system with 5K tps and watching it crash every day, but that's the extreme end of the bell curve).
Finally we couldn't put it off any more, and it was time to tackle the elephant in the room.
It's not a big Instance (5 databases, 60gb), but the challenges are big. We're dealing with 88 DTS Packages and 45 sql agent jobs, Connectivity to multiple Oracle databases, AS400 and other SQL Servers, 60+ downstream consumers of data. Excel Flat Files, Text Files, Web services, 3rd party vendor imports and exports. Let the games begin.
I knew I was screwed when I de-attached the databases from SQL 2000 and attached them to sql 2005 and got the following errors: "Attach database failed for Server x. An exception occurred while executing a T-SQL Statement or batch. Converting database x from version 539 to 611. Microsoft SQL Server, Error 195. fn_convertdatetoint_notime is not a recognized function name. Incorrect syntax near the keyword 'left'". Ultimately we determined that this issues was caused by user functions in SQL 2000 setup in the master database, NOT Supported in sql 2005. We also ran into isolated issues where there were tsql syntax errors in sql 2000 that did not throw any errors, but would not compile in 2005!
Linked Server Issues were also encountered.
Setting up a linked server to the AS400 on 64 Bit windows
Required a new version of the IBM iSeries driver
Required a patch to the IBM iseries driver
Required patching windows to install 64 bit odbc drivers
Setting up a Linked server to SQL 2000 SP4
Required patching sql 2000, http://support.microsoft.com/kb/906954
Setting up a linked server to Oracle
Over-all the process took about a month (with 4 DBA's and other work), bulk of the work was the DTS to SSIS packages. We did look at some 3rd party utilities, but they still left several hours work for each package, so we just did the brute force method and did them one at a time. Currently the process will spend 2-3 months running in parallel and being QA'd, than onto production.
Hit the "next" button.