HP ML570 - ProLiant - G2 Tuning Manual page 7

Novell NetWare 6 performance tuning guidelines for ProLiant servers
For more information regarding HP Array controllers, visit:
h18000.www1.hp.com/products/servers/proliantstorage/arraycontrollers/index.html.
The Redundant Array of Inexpensive Disks (RAID) controllers can be configured in any of
the following supported RAID levels depending on the performance level and data
protection desired.
RAID 0 – No data protection. Simply stripes data across multiple disk drives without
any data protection. This configuration provides high level of performance at low
cost.
RAID 1 – Disk mirroring. Requires twice the amount of disk drives in order to
duplicate user data for data protection. This configuration provides similar level of
performance as RAID 0 in read operations. The cost is, however, higher because of
the duplication of disks.
RAID 5 – Distributed data guarding. In this configuration, the parity data is
distributed across all drives. This provides protection against the failure of any one
drive in the array set. It provides improved performance at a minimum cost.
RAID Advanced Data Guarding (ADG) – In this configuration, two sets of parity data
is distributed across all drives. This provides the protection against the failure of any
two disk drives in the array set. This provides high fault tolerance at a minimum cost
of implementation.
The disclosure of the server configurations for this document can be found in appendix e.
The disk drive, SCSI channel, and disk controller all have to communicate with each other
during data transmission. Realize that these devices transfer data at different rates. It is
therefore recommended to balance out the I/O devices on the buses at the right speed for
optimum performance benefits.
The personal computer interconnect (PCI) / PCI-eXtension (PCI-X) bus is a 32-/64-bit
industry standard interface for high-speed data transfers between peripheral components.
For example, the standard PCI clock rate can be 33 or 66 MHz. On the other hand PCI-X,
which is an extension of the PCI, operates at up to 133 MHz. PCI-X devices are backward
compatible and adjust to the bus speed of the vendor implementation. HP servers support
several implementations. Table 3 provides some examples of theoretical PCI / PCI-X
transfer rates.
table 3. theoretical maximum achievable PCI / PCI-X transfer rates
PCI bus type
clock transfer
rate
PCI (32bit)
33 MHz bus 132 MB / s
66 MHz bus 264 MB / s
100 MHz bus
133 MHz bus
PCI (64bit) PCI-X (32bit)
264 MB / s 132 MB / s
528 MB / s 264 MB / s
400 MB / s
532 MB / s
PCI-X (64bit)
264 MB / s
528 MB / s
800 MB / s
1064 MB / s
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