No. can be on one.Would i need to get a server for the domain controller and one for exchange?
This would need to be backed up aswell i was thinking of a dell powervault md1000 but it doesnt have raid?
So you're going to rely on just onsite backups to disk? If there's a fire on the premises (for example) you will lose all the data. Is that an acceptable risk?
DAS boxes run off the scsi/sas controller that you have installed on the server, so yes it has raid as long as the controller you install has RAID