Disable Scsi-Mq Feature - Hitachi GVX-CC64G*BX User Manual

Disable SCSI-MQ feature

(1) The check of an interrupt handler (irq) number
Like the above-mentioned example, you can check by "more /proc/interrupts".
In the above-mentioned example, the numbers of the interrupt handler (irq) of I/O
processing termination processing are the left end number 35, 36, 38, and 39.
(2) A setup of interrupted CPU of an interrupt handler
# echo the bitmask of each CPU number >/proc/irq/<irq number>/smp_affinity
The example in the case of setting so that the interruption may go up to CPU#0 for the
interrupt handler of irq#35, to CPU#1 for the interrupt handler of irq#36 , and to CPU#4 for
the interrupt handler of irq#38, respectively is described below.
# echo 1 > /proc/irq/35/smp_affinity
# echo 2 > /proc/irq/36/smp_affinity
# echo 10 > /proc/irq/38/smp_affinity
Even if it performs the above-mentioned procedure, when irqbalance is starting,
interrupted CPU will be decided in OS.
Only the interrupt handler corresponding to a specific IRQ number specified in the
above-mentioned procedure goes up to CPU by specifying the starting option (--
banirq=IRQ number) of irqbalance.
The procedure of specifying the starting option (-- banirq=IRQ number) of irqbalance is
as follows.
(1) Describe the following to an irqbalance configuration file / etc/sysconfig/irqbalance.
# vi /etc/sysconfig/irqbalance:
IRQBALANCE_ARGS="$(awk '/hfcldd/{sub(":",""); printf "--banirq=" $1 " "} '
/proc/interrupts)"
(2)Restart an irqbalance daemon.
# service irqbalance restart
Enable SCSI-MQ feature
When SCSI-MQ feature and irqbalance are enabled, the optimum interrupt destination
CPU setting is done automatically.
The procedure of specifying the starting option (-h exact) of irqbalance is as follows.
(1) Describe the following to an irqbalance configuration file / etc/sysconfig/irqbalance.
# vi /etc/sysconfig/irqbalance
IRQBALANCE_ARGS="-h exact"
(2)Restart an irqbalance daemon.
# service irqbalance restart
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