Performance - HP Surestore Disk Array 12h - And FC60 Advanced User's Manual

the array for high availability, there must be no single points of failure. This means that the
configuration must have at least these minimum characteristics:
•
Two controllers connected to separate Fibre Channel loops (using separate Fibre
Channel host I/O adaptors)
•
Two disk enclosures (minimum)
•
Eight disk modules, four in each disk enclosure (minimum)
•
LUNs that use only one disk per disk enclosure.
With its dual controllers, the Disk Array FC60 provides two independent I/O paths to the
data stored on the array. Data is transmitted from the array controllers to the disks through
up to six Ultra2 SCSI channels connected to the disk enclosures. Any of several RAID
levels (1, 0/1, or 5) can be selected, however, for the greatest high availability, It is
recommended that RAID level 1 be used for optimum high availability.
The Disk Array FC60 is designed to operate with either one or two controller
Note
modules, however for high availability it is highly recommended that two
controller modules be installed.

Performance

The maximum aggregate performance that can be sustained by the disk array is
approximately 170 megabytes per second (using dual Fibre Channel-AL connections). This
performance can be achieved by configuring at least four disk modules per Ultra2 SCSI bus
utilizing the six Ultra2 SCSI channels. This can be accomplished in two ways. One way is to
configure six disk enclosures, one each per Ultra2 SCSI channel (disk enclosure full-bus
mode). In each of these enclosures, configure at least four disk modules.
Adding more disk modules to each of these disk enclosure will increase storage capacity,
but will not appreciably increase the sequential thoughput. Additional capacity may be a
worthwhile addition, since in many computing environments, capacity, not access speed, is
the limiting factor.
Another way to configure for maximum performance is to connect three disk enclosures to
the controller enclosure and configure these enclosures for split-bus operation. Then
connect an Ultra2 SCSI channel to each split bus (two channels per disk enclosure). Each
Array Design Considerations
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