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Performance Option
(-p perf) [Windows only]
This parameter improves IO handling performance (IOPS) on degradation caused by the situation that
multiple contiguous requests are stacked onto the driver. There are a few cases that this option does not
improve performance of the system, depending on the environment or I/O characteristics.
In Windows 2003, the value of perf option cannot be set, and the driver always runs with disable.
In Windows 2008 and Windows 2008 R2, the value of perf option can be set.
In Windows 2012 or later, the value of perf option cannot be set, and the driver always runs with enable.
N_Port_ID Virtualization
(-p npiv)
This parameter enables a virtual fibre channel feature with Windows Server 2012 or later Hyper-V and
RHEL KVM environment.
After enabling this parameter and executing 'hfcmgr -p <Device>' command, occasionally a message 'NPIV:
not work (-)' is displayed. It means that the virtual fibre channel feature does not work for some reasons,
such as the adapter port is linked down or the adapter port is connected directly to the disk device without
FC switch.
NPIV vport count
(-p vp)
This parameter specifies the maximum available number of virtual ports. The value is effective when the
virtual fibre channel feature is enabled on Windows Server 2012 or later Hyper-V or RHEL KVM. This
parameter can be set only with 16G Fibre Channel Adapters.
MCK Link Down Time
(-p ldm)
Time out value in seconds for the next link up after the driver recovered from a hardware error (MCK). The
parameter is set to the optimum value for a general purpose, so usually this parameter does not need to be
changed. This parameter can be set only with 16G Fibre Channel Adapters.
Link Reset Mode
(-p lr)
If the driver failed to execute an Abort Task Set command of some reason, such as a timeout, it escalates
the error recovery layer to the entire target. If the driver also failed to reset the target, it executes a brief link
down of the FC link between HBA and the I/O device, or between the HBA and a FC-Switch, as the last
resort. This option can set an I/O handling policy from below for the reset with brief link down.
The driver makes the HBA port offline immediately and returns all I/Os received after the reset as I/O Error.
The driver keeps the HBA port online, and if the OS retried to issue once failed commands to the driver, the
driver keeps the retried I/Os and waits for a link up to execute them on the linked up path.
If this parameter is set to "multi", then the driver works with policy (a), and if the parameter is set to "single",
the driver works with policy (b). This parameter can be set only with 16G Fibre Channel Adapters.
Link Init negotiation Timer
This parameter specifies the time out value in seconds to wait for a link negotiation when the server reboot.
This parameter can be set only with 16G Fibre Channel Adapters.
Target Restrain
(-p trs) [Linux only]
This parameter specifies inhibiting to issue reset commands for entire targets. The parameter is set to the
optimum value for a general purpose, so usually this parameter does not need to be changed. This
parameter can be set only with 16G Fibre Channel Adapters.
Core Control
(-p cc)
16G Fibre Channel Adapters with 1port or 2port have multiple cores per port. The driver can distribute I/O
loads on multiple cores by the following policies.
Displayed value
minq [Linux only]
round robin
[Windows only]
iosize
cpun [Linux only]
This parameter can be set only with 16G Fibre Channel Adapters.
(-p lit)
Description
Count command numbers on each core's response waiting
queue and choose the least core to issue a new command.
Round-robin scheduling by the core number.
Use previously chosen core if the command size exceeds the
user-specified size.
If the driver received a command smaller than the user-specified
size and the previously chosen core is processing other
command exceeding the user-specified size, the driver chooses
a core other than the previously chosen core.
Choose a core by the CPU number that issued the I/O
command.
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