Overview of RAID for IP Video Storage
RAID 50:
RAID 50 combines the block striping and parity of RAID 5 with the straight block striping of RAID 0 and requires a minimum of 6 drives. In essence it takes the data of multiple RAID 5 sets and then stripes it across all drives. Adding RAID 0 to multiple RAID 5 sets allows you to increase the write performance of a straight RAID 5 set as well as increase the level of fault tolerance. A RAID 50 can lose as many drives as there are individual RAID 5 sets.
Tip: You can estimate a RAID 50 array’s usable capacity by this simple equation, [R *(n-1)]*s = U. Where R is the raw capacity of one hard drive, n is the number of hard drives in a single RAID 5 array, s is the number of RAID 5 arrays being striped and U is the usable capacity of the array.
RAID 60:
RAID 60 is similar to RAID 50 except it combines the straight block-level striping of RAID 0 with the distributed double parity of RAID 6. That is, a RAID 0 array striped across RAID 6 elements. It requires at least 8 disks.
Tip: You can estimate a RAID 50 array’s usable capacity by this simple equation, [R *(n-2)]*s = U. Where R is the raw capacity of one hard drive, n is the number of hard drives in a single RAID 5 array, s is the number of RAID 5 arrays being striped and U is the usable capacity of the array.
