|
These controller support RAID levels 0, 1, 1E and 10E. See below for a short description of these RAID types. Additional detail can be found in the RAID controller software user's guide.
Level 0: Often called "striping," is a performance-oriented data mapping technique. Data written to the array are divided into stripes and written across the disks of the array. This procedure enables high I/O performance at a low cost but provides no redundancy.
Level 1: Often called "mirroring," provides redundancy by writing identical data to each member disk of the array. Level 1 operates with two disks that may use parallel access for high data-transfer rates when reading, but more commonly operates independently to provide high I/O transaction rates. Level 1 provides very good data reliability and improves performance for read-intensive applications but at a relatively high cost. Minimum number of drives is two.
Level 1E: RAID level 1E is also referred to as RAID level 1 "Enhanced". In terms of RAID, it can be thought of as enhanced mirroring or striped mirroring. The name sounds like RAID 10, but RAID 1E uses an odd number of disks to achieve data protection while RAID 10 requires the use of an even number of disks. RAID 1E strips data across all disks in the array like RAID 0. However, RAID 1E takes a copy of the data and then strips it across all of the disks as well. RAID 1E shifts the second copy of the data over on each physical disk to move the data stripe copies to other disks. Minimum number of drives is three.
Level 10E: Level 1E is enhanced mirroring, which offers the same functionality as RAID 10 on an odd number of drives, starting with three. RAID 10E is the same as RAID 1E, but on an even number of drives. Minimum number of drives is four.
This applies to:
|