Then you only have three options: 1. Leave it as is (recommended and standard).  If the drives are configured in a RAID 1 (or mirror), then either drive can fail and your data will stay accessible, giving you the chance to replace the drive without so much as a reboot.  In this configuration, the SAS 5/iR manages the RAID 1 (mirror), and presents the OS with a single "disk" to use.  Because each drive is a mirror of the other, you would 1) only see the "mirror" in the OS, rather than the individual disks, and 2) only see the disk space of a single disk. 2. Create a RAID 0 (stripe).  This is not recommended, because if a single disk fails, all data on both disks will be inaccessible/gone.  There can be some performance improvements in this configuration, but should not be used unless a rigorous backup plan is in place.  In this configuration, your OS will see a single disk of 146GB (somewhat less will actually be usable). 3. Use the controller in non-RAID mode.  This treats each drive as an individual disk, performing no RAID functions.  This is no different than having multiple disks connected to onboard ports on a motherboard - one disk dies, then the contents of that drive will be inaccessible/gone.  In this configuration, your OS will actually see two separate 73GB disks.
I just procured a Dell PowerEdge 840 on sale.   It appears to have 4x70gb  SAS drives in RAID configuration that shows only 1x70gb drive.   How can I reset the RAID array so that I have access to all 4 drives?
Changing RAID on PowerEdge 840