Managing Serviceguard Eighteenth Edition, September 2010

Examples of Storage on Disk Arrays
Figure 3-23 shows an illustration of storage configured on a disk array. Physical disks
are configured by an array utility program into logical units or LUNs which are then
seen by the operating system.
Figure 3-23 Physical Disks Combined into LUNs
NOTE: LUN definition is normally done using utility programs provided by the disk
array manufacturer. Since arrays vary considerably, you should refer to the
documentation that accompanies your storage unit.
Figure 3-24 shows LUNs configured with multiple paths (links) to provide redundant
pathways to the data.
NOTE: Under agile addressing, the storage units in these examples would have names
such as disk1, disk2, disk3, etc. See “About Device File Names (Device Special
Files)” (page 106)
As of A.11.20, Serviceguard supports cluster-wide DSFs, and HP recommends that you
use them. See “About Cluster-wide Device Special Files (cDSFs)” (page 135).
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110 Understanding Serviceguard Software Components