HSG80 ACS Solution Software Version 8.7 for Compaq Tru64 UNIX Installation and Configuration Guide

Planning Storage Configurations
2–18 HSG80 ACS Solution Software Version 8.7 for Compaq Tru64 UNIX Installation and
Configuration Guide
Planning Considerations for Storageset
This section contains the guidelines for choosing the storageset type needed for your
subsystem:
• “Stripeset Planning Considerations,” page 2–18
• “Mirrorset Planning Considerations,” page 2–21
• “RAIDset Planning Considerations,” page 2–22
• “Striped Mirrorset Planning Considerations,” page 2–24
• “Storageset Expansion Considerations,” page 2–26
• “Partition Planning Considerations,” page 2–26
Stripeset Planning Considerations
Stripesets (RAID 0) enhance I/O performance by spreading the data across multiple
disk drives. Each I/O request is broken into small segments called “chunks.” These
chunks are then simultaneously “striped” across the disk drives in the storageset,
thereby enabling several disk drives to participate in one I/O request.
For example, in a three-member stripeset that contains disk drives Disk 10000, Disk
20000, and Disk 10100, the first chunk of an I/O request is written to Disk 10000, the
second to Disk 20000, the third to Disk 10100, the fourth to Disk 10000, until all of
the data has been written to the drives (Figure 2–5).
Figure 2–5: 3-member RAID 0 stripeset (example 1)
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