Show Table of Contents
Chapter 26. Fibre Channel
This section discusses the Fibre Channel API, native Red Hat Enterprise Linux 6 Fibre Channel drivers, and the Fibre Channel capabilities of these drivers.
26.1. Fibre Channel API
Following is a list of
/sys/class/
directories that contain files used to provide the userspace API. In each item, host numbers are designated by H
, bus numbers are B
, targets are T
, logical unit numbers (LUNs) are L
, and remote port numbers are R
.
Important
If your system is using multipath software, Red Hat recommends that you consult your hardware vendor before changing any of the values described in this section.
- Transport:
/sys/class/fc_transport/targetH:B:T/
port_id
— 24-bit port ID/addressnode_name
— 64-bit node nameport_name
— 64-bit port name
- Remote Port:
/sys/class/fc_remote_ports/rport-H:B-R/
port_id
node_name
port_name
dev_loss_tmo
: controls when the scsi device gets removed from the system. Afterdev_loss_tmo
triggers, the scsi device is removed.Inmultipath.conf
, you can setdev_loss_tmo
toinfinity
, which sets its value to 2,147,483,647 seconds, or 68 years, and is the maximumdev_loss_tmo
value.In Red Hat Enterprise Linux 6,fast_io_fail_tmo
is not set by default, hencedev_loss_tmo
value is capped to 600 seconds.fast_io_fail_tmo
: specifies 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 untildev_loss_tmo
expires and the queue is unblocked.Iffast_io_fail_tmo
is set to any value exceptoff
,dev_loss_tmo
is uncapped. Iffast_io_fail_tmo
is set tooff
, no I/O fails until the device is removed from the system. Iffast_io_fail_tmo
is set to a number, I/O fails immediately whenfast_io_fail_tmo
triggers.
- Host:
/sys/class/fc_host/hostH/
port_id
issue_lip
: instructs the driver to rediscover remote ports.
Where did the comment section go?
Red Hat's documentation publication system recently went through an upgrade to enable speedier, more mobile-friendly content. We decided to re-evaluate our commenting platform to ensure that it meets your expectations and serves as an optimal feedback mechanism. During this redesign, we invite your input on providing feedback on Red Hat documentation via the discussion platform.