Appendix C. Terminology 785
Security Key Lifecycle Manager
Security Key Lifecycle Manager (SKLM) centralizes, simplifies, and automates the encryption 
key management process to help minimize risk and reduce operational costs of encryption 
key management.
Serial-attached SCSI
SAS is a method that is used in accessing computer peripheral devices that employs a serial 
(1 bit at a time) means of digital data transfer over thin cables. The method is specified in the 
American National Standard Institute standard called SAS. In the business enterprise, SAS is 
useful for access to mass storage devices, particularly external hard disk drives.
Service Location Protocol 
The Service Location Protocol (SLP) is an internet service discovery protocol that enables 
computers and other devices to find services in a local area network (LAN) without prior 
configuration. It was defined in the request for change (RFC) 2608.
Small Computer System Interface (SCSI)
Small Computer System Interface (SCSI) is an ANSI-standard electronic interface with which 
personal computers can communicate with peripheral hardware, such as disk drives, tape 
drives, CD-ROM drives, printers, and scanners, faster and more flexibly than with previous 
interfaces.
Snapshot
A snapshot is an image backup type that consists of a point-in-time view of a volume.
Solid-state disk
A solid-state disk (SSD) or Flash Disk is a disk that is made from solid-state memory and 
therefore has no moving parts. Most SSDs use NAND-based flash memory technology. It is 
defined to the Storwize V7000 as a disk tier generic_ssd.
Space efficient
See “Thin provisioning” on page 786.
Spare
An extra storage component, such as a drive or tape, that is predesignated for use as a 
replacement for a failed component.
Spare goal
The optimal number of spares that are needed to protect the drives in the array from failures. 
The system logs a warning event when the number of spares that protect the array drops 
below this number.
Space-efficient volume 
For more information about a space-efficient volume, see “Thin-provisioned volume” on 
page 786.
Stand-alone relationship
In FlashCopy, Metro Mirror, and Global Mirror, relationships that do not belong to a 
consistency group and that have a null consistency-group attribute.