Configuring Units
30 3ware 9000 Series Serial ATA RAID Controller Installation Guide
cause a system hang, depending on your operating system.
RAID 0 arrays are not recommended for high availability
systems unless additional precautions are taken to prevent
system hangs and data loss.
RAID 1. Also known as a mirrored array. Mirroring is done on
pairs of drives. Mirrored disk arrays write data to two drives
using RAID 1 algorithms. This gives your system fault
tolerance by preserving the data on one drive if the other drive
fails. Fault tolerance is a basic requirement for mission critical
systems like web and database servers.
RAID 5. Combines striping data with parity (exclusive OR) to
restore data in case of a drive failure. This array type provides
performance, fault tolerance, high capacity, and storage
efficiency. Requires a minimum of three drives.
RAID 10. This array is a combination of RAID 1 with RAID 0.
Striped and mirrored arrays for fault tolerance and high
performance. Requires a minimum of four drives to use both
RAID 0 and RAID 1 techniques.
RAID 50. This array is a combination of RAID 5 with RAID 0.
This array type provides fault tolerance and high performance.
Requires a minimum of six drives.
Single Disk. A single drive that has been configured as a unit
through 3ware software (3BM, 3DM 2, or CLI). Like disks in
other RAID configurations, single disks contain 3ware Disk
Control Block (DCB) information and are seen by the OS as
available units.
Single drives are not fault tolerant and therefore not
recommended for high availability systems unless additional
precautions are take to prevent system hangs and data loss.
JBOD. A JBOD is an unconfigured disk attached to your 3ware
RAID controller. JBOD configuration is no longer supported in
the 3ware 9000 series. AMCC recommends that you use Single