RAID DefinedRAID, short for Redundant Array of Independent Disks, is a combination of two or more disks with the aim of providing fault tolerance and improving performance. There are several different levels of RAID, with each providing a different method of sharing or distributing data amongst the drives.
DNS Series RAID Support- DNS-343: RAID 0, 1, 5
- DNS-320, DNS-321, DNS-323, and DNS-325: RAID 0,1
RAID Types- RAID 0 provides data striping, which spreads out blocks of data over both drives, but does not provide data redundancy. Although performance is improved, the lack of fault tolerance means that if one drive fails, all data in the array will be lost.
- RAID 1 provides mirroring over both disks, with the same read/write speed of a single disk. A RAID 1 array can only be as large as it’s smallest member disk. Because the data is stored on both disks, RAID 1 provides fault tolerance and protection, in addition to performance advantages.
- RAID 5 provides data striping with distributed parity, which stores information that can be used to reconstruct data. A RAID 5 array will be the size of all the combined disks capacity less the capacity of one disk, e.g. If there are 4x 80GB disks in the array, the arrays capacity will be 240GB (3x80GB). Implementing RAID 5 on the DNS-343 allows it to continue operating even if one of the disks fails. The diagram below indicates the operation of RAID 5.
