HP RAID Software for OpenVMS provides ways to
configure and use disk drives so that they achieve improved I/O performance.
RAID (redundant arrays of independent disks) uses striping technology
to chunk data and distribute it across multiple drives. RAID software
is available in various levels, one of which is volume shadowing. Table 10-1 describes RAID levels.
Table 10-1 RAID Levels
| RAID Level | Description |
|---|
Level
0 | Striping with
no redundancy. |
Level
1 | Shadowing. |
Levels
0 + 1 | Striping and
shadowing together. |
Level
3 | Striped data with
dedicated parity drive. Drives are rotationally synchronized. |
Level
5 | Striped data and
parity. |
Level 6 | Striped data and parity with two
parity drives. |
Shadowing striped drives can increase both performance
and availability, because you can achieve faster response time with
striping and data redundancy with shadowing. In addition to shadowing
striped sets, you can also stripe shadow sets. Each strategy offers
different advantages and tradeoffs in terms of availability, performance,
and cost.
