Avago Technologies LSI20320 - Manual (Page 24)

18 Fusion-MPT FCode User’s Guide
Copyright © 2000-2004 by LSI Logic Corporation. All rights reserved.
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depth = 4
With these settings the host is interrupted only once for four I/Os
processed by the chip, unless a time of 160 microseconds has passed
since the host was last interrupted.
Although LSI Logic has determined that these settings are optimal for a
wide variety of situations, your system’s I/O load may benefit from a
deeper queue or a longer timeout. LSI Logic provides a mechanism to
modify these values and write them to the nonvolatile EEPROM on the
adapter.
To change the interrupt coalescing values, first select the port or adapter
shown (use the port name your system assigns). Then use the show-
interrupt-coalescing and set-interrupt-coalescing commands, as
shown in the example below:
ok select /pci@8,700000/IntraServer,fc@1
ok show-interrupt-coalescing
Interrupt coalescing timeout is a0 (160 decimal) microseconds
Interrupt coalescing depth is 4 (4 decimal)
ok set-interrupt-coalescing <- command with no arguments prints help
usage is set-interrupt-coalescing
ok 100 8 set-interrupt-coalescing
Interrupt coalescing timeout selected is 100 (256 decimal) microseconds
Interrupt coalescing depth selected is 8 (8 decimal)
Interrupt coalescing has been set
Change will take effect after system reset
Note: The system must be power cycled for the changes to take
effect. It is not sufficient to execute the reset-all command.
4.5 Multi-Pathing
The Multi-Pathing option recognizes the need to provide a unique logical
ID for each port of dual ported target. If a dual ported target is attached
to a single channel of the 929, enabling the Multi-Pathing option creates
two logical IDs for the single drive, one for each port on the drive. If Multi-
Pathing is disabled, the 929 recognizes that both ports on the target
actually address the same drive, so only a single Logical ID is created
for the drive. Each of these configurations has its application; however,
careful analysis of the system and topology requirements is advised. The
Intel BIOS, the Solaris BIOS, and the FcUtil utility all provide the Multi-