HP StorageWorks 3000 RAID Array - Manual (Page 46)

2-4 RAID Array 3000 Controller Shelf Hardware User’s Guide
Compaq Confidential – Need to Know Required
Writer: Bob Young Project: RAID Array 3000 Controller Shelf Hardware User’s Guide Comments:
Part Number: EK-SMCPQ-UG. D01 File Name: c-ch2 RAID Array 3000 Controller.doc Last Saved On: 12/4/00 1:08 PM
From the storage shelf’s perspective, the controller receives the I/O requests
from the host and directs them to the devices. Since the controller processes all
the I/O requests, it eliminates the host-based processing that is typically
associated with reading and writing data to multiple storage devices.
The controller does much more than simply manage I/O requests: it provides
the ability to combine several ordinary disk drives into a single, high-
performance storage unit called a storageset. Storagesets are implementations
of RAID technology, also known as a Redundant Array of Independent Disks.
Every storageset shares one important feature: whether it uses two disk drives
or 12, each storageset looks like a single storage unit to the host.
You create storage units by combining disk drives into storagesets such as
stripesets, RAIDsets, and mirrorsets, or by presenting them to the host as
single-disk units (see Figure 2– 3).
Mirrorset
Partitioned
Storageset
Stripeset
Partitioned
Disk Drive
Striped
Mirrorset
Raidset
Disk Drives
3000-24
Figure 2-3. Storagesets, partitions, and disk drives