Compaq StorageWorks HSG60 ACS Solution V8.6 for SGI IRIX Installation and Configuration Guide

2–14 HSG60 ACS Solution Software Version 8.6 for SGI Irix Installation and Configuration Guide
Figure 2–9. Mirrorsets maintain two copies of the same data
Figure 2–10. Mirrorset example 2
Keep these points in mind as when planning mirrorsets:
■ Data availability with a mirrorset is excellent but comes with a higher cost—you
need twice as many disk drives to satisfy a given capacity requirement. If
availability is your top priority, consider using dual-redundant controllers and
redundant power supplies.
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CXO7288A
A'A
B'
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Mirror drives contain
copy of data
Operating
system
view
Actual
device
mappings
Mirrorset
CXO4594B
Disk 1
Block 0
Block 1
Block 2
etc.
Disk 2
Block 0
Block 1
Block 2
etc.
Virtual disk
Block 0
Block 1
Block 2
etc.