I have recently been doing vCenter 2.5/4.0 to vCenter 4.1 upgrades and migrations for our clients. Upgrades to 4.1 have been more difficult than doing upgrades to 4.0 because vCenter 4.1 requires an x64 version of Windows.
Most of our clients that are on vCenter 2.5 are running it on 32-bit versions of Windows with most of those being Windows 2003.
For these migrations we have mostly been building new Windows 2008 R2 virtual machines and using the new vCenter Data Migration tool – Migrating an existing vCenter Server database to 4.1 using the Data Migration Tool
The data migration tool is handy for backing up the SSL certificates and registry settings from the vCenter 2.5 server and then restoring those to the new vCenter 4.1 server. The tool will also backup and restore SQL Express databases but most of our clients are running full SQL.
On my most recent upgrade/migration I ran into an SQL issue that I hadn’t seen before. In this case the client was running SQL 2005 as their database server for vCenter 2.5. Since they were already running SQL 2005 we didn’t see the need to move the database or upgrade SQL since 2005 is supported by vCenter 4.1.
During the install of vCenter 4.1 the database upgrade processes started as normal but then about 5 minutes into it we received this error “Exception Thrown while executing SQL script” and the install was halted. We immediately looked at the vCenter install log (vminst.log) to investigate what happened. The log had some additional SQL logging information but nothing specific so I then Googled the exception message and the first link in the search results was just what I was looking for.
The issue was due to the fact that the vCenter database was set to SQL 2000 compatibility mode. The reason it was set like this is because this server was originally SQL 2000 and then upgraded to SQL 2005.
The fix wasn’t as easy as just changing the database to SQL 2005 compatibility because the failed upgrade left the database in an inconsistent state. To correct the issue we first had to restore the database from the backup we made before the upgrade and then change the compatibility mode to 2005.
The other issue we ran into was more of an annoyance than an issue. After upgrading vCenter to 4.1 and installing vCenter Converter we noticed this error in the vCenter Service Status tool “Unable to retrieve health data from https://<VC servername or IP address>/converter/health.xml”. A quick Google search led us to the fix for this. – vCenter Service Status displays an error for com.vmware.converter
Jeremy Waldrop's Blog 