1.6. Storage Components

Disk drives are a relatively fast, reliable, and economic way to store and access data, applications, and operating systems. Server storage typically consists of removable storage and permanent storage.

Removable storage includes CD-ROM drives, disk drives, and tape backup drives.

Permanent storage includes IDE disk drives and SCSI disk drives.

1.6.1 Drive Arrays

HP is a leader in drive array storage technology. An array, sometimes called a RAID array, is a set of disks that acts like a large single disk, thereby providing higher performance and data fault tolerance than a multidisk system.

Because storage needs have expanded beyond the server and the types of storage devices have increased, the need for a high-speed connection between servers and storage devices has become critical. Storage solutions designed to meet these needs include the following:

• Direct-attached storage (DAS) Storage devices directly, internally, or externally connected to the server, such as disk drives, tape drives, and external storage systems.

• Storage area network (SAN) A dedicated, centrally managed, secure information infrastructure network that enables direct physical access to common storage devices or a storage pool.

• Network attached storage (NAS) Dedicated, self-contained, intelligent servers that attach directly to the existing LAN. Data is transferred to and from clients over industry-standard network protocols using industry-standard file-sharing protocols.

• HP Enterprise Network Storage Architecture (ENSA) Brings SAN, NAS, and DAS together in an architecture that meets enterprise storage requirements.