If you're using hardware raid (for the boot drive), you have a PERC. This controller doesn't support non-raided drives. Therefor a single drive would need to be configured as a single disk raid 0. This also means that each time you pull a drive, you 'fail' the raid 0 and the controller will beep at you that your raid 0 failed. The drive bays are made for hotswapping, but most admins will not tempt this capability by swapping drives each week. I'd suggest to look for a real backup solution like a tape drive or cartridge solution (e.g. Dell RD1000) or so.
I have a Dell R515. It has a bunch of hot swap drives and bays. We are only using HW raid on the boot drive. The rest of the drives are individual drives. eg H:\   I:\   J:\ etc. We want to use one (or more) of these drives for a bank backup. In other words back up to the drive then. Every week just pull the drive and put it into the bank. Can you do this. I know that in raid situations if a drive fails there are various things build in to allow this. But just a basica or dynamic single drive, Im a little aprehensive to do this.  Also If this is allowed should I turn write caching off in policies of the drive "Enable write caching on the disk" and also turn off "Enable advanced performance" on the same policies window of the drive. Thanks.
Swapping drives ?