Storage Subsystem Hardware Services

This segment includes other storage subsystem services and redundant array of independent disks (RAID)-based storage system services.

• RAID-based storage system services — This category includes the total of all external controller-based RAID-based disk storage, host-based external RAID storage, host-based internal RAID storage and network-attached storage. RAID refers to a set of disk drives (at least two) with input/output activity that is managed by external-based or host-based RAID technology.
• Other storage subsystem services — This category includes tape libraries, optical libraries and hard-disk drive upgrades/replacements.