My name is Pete Rodriguez and I am a SharePoint architect in the Microsoft Technology Center in Chicago. In the past year and half we've had a number of customers come in for a SharePoint upgrade lab (typically a 3 day event) and I'd like to share some of the common issues and learnings I’ve run across during these engagements.
Not enough Free Disk Space in SQL Server
Historically, this has been the biggest showstopper for us in the lab that halts the upgrade process. If you do a gradual upgrade, make sure you have at least 3.5 to 4 times the size of your content database available as free space. The TechNet documentation at http://technet.microsoft.com/en-us/library/cc262891.aspx recommends three times but we had one customer run out of space even though we had exactly three times the amount of free space available (go figure). The reason you will need so much free space during a gradual upgrade is because you will have to account for these items in SQL Server:
Original content database
This is your original content database from SharePoint 2003.
Temporary Content Database
This is usually named something like WSS_Temp_<GUID>. When you select an individual site collection to upgrade during the upgrade process, your site collection gets copied to this temporary content database and then upgraded. This database gets deleted once it is copied into the new content database (typically named the same as your original content database followed by _PAIR).
New _PAIR content database
Once your content gets upgraded it gets copied into this database.
Transaction logs
These can get really large during the upgrade process (I have seen 10% the size of the content database). You could switch to simple (rather than full) logging in SQL Server during the upgrade process to eliminate this issue.
One trick you can do if you run out of free space on your SQL Server would be to do the following:
· Add a new larger disk to the server but don’t give it a drive letter
· Stop SQL Server and rename the Data directory to Data.old
· Create a new Data folder (make sure it stays empty)
· Go into Disk Management, select your new disk and right-click to select Change Drive Letters and Path. Click the Change button and select Mount in the following empty NTFS folder and browse to your New Data folder.
· Copy the databases from Data.old to Data
· Delete the Data.old folder
· Restart SQL Server
Using third party components
Some third party components may not work properly after the upgrade. One customer was using a third party recycle bin (http://mindsharpblogs.com/todd/archive/2005/10/06/719.aspx) that took considerable effort to remove after the upgrade. Check with the vendor prior to upgrade to see if they have a later version available.
Using SSL with gradual upgrade
If you are planning to do a gradual upgrade, are using SSL, and are planning to use host headers, make sure you get a wildcard certificate from a certificate authority before doing an upgrade. Alternatively, you could use IP bound web applications in IIS.
Using Kerberos with gradual upgrade
If you are using Kerberos today with SharePoint 2003, make sure you create a service principal name in Active Directory for the temporary URL for the SharePoint 2003 content. See the following article for more information on how to configure an SPN: http://support.microsoft.com/kb/832769
Consider the impact of a gradual upgrade on Office users
Until you upgrade the SharePoint 2003 to 2007, users will have to contend with a different URL for the 2003 content. For example, if a user browses to http://portal/sites/teamsite and this site has not been upgraded to SharePoint 2007, then the user will be redirected to http://portal-old/sites/teamsite. However, this redirect will only work in a web browser. If a user attempts to open a document directly in Microsoft Office, this will not work: Office is not be able to use this type of redirect so an error message will appear to the user. However, once the site has been upgraded, Office will work properly. As a workaround, a user could open a document using the temporary URL (e.g. http://portal-old).
Perform a trial upgrade
Make sure you do a trial upgrade before actually upgrading your production environment. The easiest way to accomplish this is to use Virtual Machine Manager 2007 (note that you can download a trial version at http://technet.microsoft.com/en-us/scvmm/bb727241.aspx) and create virtual machines for your domain controller, SharePoint servers, and SQL Server. You can even create these VM’s while your servers are running. Also, if you have Windows Server 2008 x64, you should consider upgrading these virtual machines to run in Hyper-V. I’ve seen the speed of the upgrade process increase significantly (three times faster) on Hyper-V compared to running on Virtual Server.