Advice - is it standard practice to have all Domain cont. operations on one server?

[maxrebo]

As per title - I have all the Domain controller operations on our PDC (Schema Master, operations master etc...)

Is this the recommended way or is it best to split them over a few domain controllers?

(Just thinking with the (god forbid!) possibility of this server going offline)

 

Thanks

[JRowley]

Typically I believe you should spread them out if possible, however failing that having them all on one server is ok provided you have a spare DC which can seize the roles in the event of the primary falling apart, though seizing is something you should avoid if possible.