Today I migrated a Microsoft SBS 2003 Server to a VMware ESXi 5.0 host.
At first I tried to convert the running server using the VMware vCenter Converter. It finished quite fast (~40GB in half an hour) over gigabit ethernet and even booted up. But instead of showing the login form, it reported, that the ActiveDirectory could not be started. I tried all the suggested solutions provided by Microsoft’s knowledge base article (KB240655) without success.
Then I used Seagate’s DiscWizard from the Hiren BootCD to create an Acronis disk images and migrated it using the converter. At first it estimated over 5 hours, so I changed some settings (nothing really special) – the next try took only 30! minutes. Additionally this time no error showed up and everything worked as expected!
Fazit: Always do an offline migration – it will save you hours!