>Can I go straight from NetWare 6.5 SP2 to SP4a?

Yes. However I have a tip for you:
If you want to take advantage of the new OES features of SP4a, do not
install SP4a as a support pack, but rather "upgrade" your server using the
SP4a overlay CDs. That way, you will get iManager 2.5 and other components
that otherwise would not be udpated.

Marcel Cox (using XanaNews