Assuming you have a PERC 5/6, it is important to know that the PERC does NOT support non-RAID.  So, if you want to use a disk as a standalone drive, you must first configure it in a RAID array.  The only RAID level that will accept one disk is RAID 0.  You can do this from within OMSA inside the OS (Storage, PERC, Information/Configuration, Create/New from dropdown for controller), or you can do it from the CTRL-R utility during POST (highlight controller, F2, Create/New - be sure to check Advanced and Initialize boxes). (Reconfigure is the option you would choose to add it to your existing RAID 5 to expand its size.)
I need to add a hard drive for storage on a poweredge 2900.  There are 4 HDD's in a RAID 5 array but I do not want to add the new hard drive into the array.  I've installed the hard drive but unable to initialize the disk and get it online.  Is there something that needs to be done first?  In the OSMA I don't have the options to re-configure, only blink and add as hot spare. Thanks,
Adding hard drive to poweredge 2900