Online Disk Suite (ODS)

Sun's volume manager has many names

• Online Disk Suite (ODS) - will be using this name in this document
• Solstice Disk Suite (SDS)
• Solaris Logical Volume Manager (Solaris LVM)

ODS is a disk storage management solution, which offers

• High Availability
• Improved Performance
• Simplified disk management

Raid Levels
The disk management software offers the common raid levels

raid 0 (Striping)	A number of disks are concatenated together to give the appearance of one very large disk. Advantages    Improved performance    Can Create very large Volumes Disadvantages    Not highly available (if one disk fails, the volume fails)
raid 1 (Mirroring)	A single disk is mirrored by another disk, if one disk fails the system is unaffected as it can use its mirror. Advantages    Improved performance    Highly Available (if one disk fails the mirror takes over) Disadvantages    Expensive (requires double the number of disks)
raid 5	Raid stands for Redundant Array of Inexpensive Disks, the disks are striped with parity across 3 or more disks, the parity is used in the event that one of the disks fails, the data on the failed disk is reconstructed by using the parity bit. Advantages    Improved performance (read only)    Not expensive Disadvantages    Slow write operations (caused by having to create the parity bit)