(requires 3+ drives) - data block is striped at byte level across drives and error correction codes (parity info) is recorder on another drive. Provides fault tolerance but slower writing performance.
Redundant Array of Inexpensive Disks – parallel array with parity. The distinguishing feature of level 3 is a single parity drive to accomplish redundancy. This is achieved by interleaving the parity information at the byte level. Typically, the drive spindles are synchronized. It still requires that all disks in a group be accessed, even for small transfers, with the wait for the slowest to finish before the transfer is complete. Spindle synchronization is expensive and often limits the choice of disk elements. See also RAID.
Striping (small stripe size) with one parity disk.
RAID 3 provides data redundancy by using data striping in combination with parity information. Data is striped across the array disks, with one disk dedicated to parity information. If a drive fails, the data can be reconstructed from the parity. See also Parity, RAID, and Striping.
As fast as RAID 0 for reading but slow at writing due to adding the parity data. Uses parity, which is a special error correction code allowing data on a failed drive to be rebuilt from the data on the others. 1 drive is used, sharing data at the byte level.
A form of RAID protection that uses at least three drives, where one drive holds all of the parity data. The other two or more drives contain data striped...
RAID 3 implements block striping with dedicated parity. This RAID level breaks data into logical blocks, the size of a disk block, and then stripes these blocks across several drives. One drive is dedicated to parity. In the event a disk fails, the original data can be reconstructed from the parity information. In RAID 3, the total disk capacity is equivalent to the sum of the capacities of all drives in the combination, excluding the parity drive. Thus, combining four 1GB drives, for example, would create a single logical drive with a total disk capacity of 3GB. This combination appears to the system as a single logical drive. RAID 3 provides increased data transfer rates when data is being accessed in large chunks or sequentially. However, in write operations that do not span multiple drives, performance is reduced since the information stored in the parity drive needs to be re-calculated and re-written every time new data is written to any of the data disks.
RAID 3 functionality divides data blocks and distributes (stripes) the data across a disk array, providing parallel access to data. RAID 3 provides data availability; a separate disk stores redundant parity information that is used to regenerate data if a disk fails. It requires an extra disk for the parity information. RAID 3 increases bandwidth, but it provides no improvement in the throughput. RAID 3 can improve the I/O performance for applications that transfer large amounts of sequential data.
A RAID 3 uses byte-level striping with a dedicated parity disk. RAID 3 is very rare in practice. One of the side effects of RAID 3 is that it generally cannot service multiple requests simultaneously. This comes about because any single block of data will by definition be spread across all members of the set and will reside in the same location, so any I/O operation requires activity on every disk.
