Red Hat Summit8.3. Fibre Channel configuration files
Learn about Fibre Channel configuration files, their structure in the /sys/class/ directory, key variables, and recommendations for adjusting device parameters safely in environments using multipath software.
The following is the list of configuration files in the /sys/class/ directory that provide the user-space API to Fibre Channel.
The items use the following variables:
H- Host number
B- Bus number
T- Target
L- Logical unit (LUNs)
R- Remote port number
Consult your hardware vendor before changing any of the values described in this section, if your system is using multipath software.
Transport configuration in /sys/class/fc_transport/targetH:B:T/
port_id- 24-bit port ID/address
node_name- 64-bit node name
port_name- 64-bit port name
Remote port configuration in /sys/class/fc_remote_ports/rport-H:B-R/
-
port_id -
node_name -
port_name dev_loss_tmoControls when the scsi device gets removed from the system. After
dev_loss_tmotriggers, the scsi device is removed. In themultipath.conffile , you can setdev_loss_tmotoinfinity.In Red Hat Enterprise Linux 10, if you do not set the
fast_io_fail_tmooption,dev_loss_tmois capped to600seconds. By default,fast_io_fail_tmois set to5seconds in Red Hat Enterprise Linux 10 if themultipathdservice is running; otherwise, it is set tooff.fast_io_fail_tmoSpecifies the number of seconds to wait before it marks a link as "bad". Once a link is marked bad, existing running I/O or any new I/O on its corresponding path fails.
If I/O is in a blocked queue, it will not be failed until
dev_loss_tmoexpires and the queue is unblocked.If
fast_io_fail_tmois set to any value except off,dev_loss_tmois uncapped. Iffast_io_fail_tmois set to off, no I/O fails until the device is removed from the system. Iffast_io_fail_tmois set to a number, I/O fails immediately when thefast_io_fail_tmotimeout triggers.
Host configuration in /sys/class/fc_host/hostH/
-
port_id -
node_name -
port_name issue_lipInstructs the driver to rediscover remote ports.
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