R

• Rack unit (U): A rackmount measurement of 1.75 inches (44.45 millimeters) of height. The height of rackmount devices is in Us, such as 1U, 2U, 3U, or a 4U half-rack mount.
• Rackmount: A two- or four-rail vertical structure for servers and other rack-mount devices.
• RAID 0: Disk striping to multiple disk drives.
• RAID 1: Mirrors data to another disk volume.
• RAID 10: Combines the mirroring of RAID 1 with the striping of RAID 0, but without parity.
• RAID 5 – RAID 0 with parity added.
• RAID 6 – RAID 5 with the parity doubled.
• Random access memory (RAM): The volatile storage area that serves as a conduit for program instructions, data, and addressing going to or coming from the CPU.
• RAS Precharge (tRP): The time required to release the active row in memory.
• Recovery point objective (RPO): The target point-in-time to be reestablished through data recovery for a failed system...