Users Guide

Broadcom DRVLin-LPe-UG124-100

Emulex Drivers for Linux User Guide

-r--r--r-- 1 root root 4096 Feb 28 17:03 /sys/class/scsi_host/host7/lpfc_topology

-rw-r--r-- 1 root root 4096 Feb 28 17:03 /sys/class/scsi_host/host7/lpfc_use_adisc

Temporary Configuration Parameters with sysfs:

In the previous example, notice that the FC driver parameters are available as files. Reading a file displays the current value

of a driver parameter. If the permissions allow it, you can write a value to the file and it will take effect immediately.

Reading the lpfc_log_verbose file might show that its value is 0:

cat /sys/class/scsi_host/host7/lpfc_log_verbose

To modify the lpfc_log_verbose value to 0xffffffff:

echo 0xffffffff > /sys/class/scsi_host/host7/lpfc_log_verbose

Reading the lpfc_log_verbose file now shows a value of 0xffffffff:

cat /sys/class/scsi_host/host7/lpfc_log_verbose

0xffffffff

NOTE: Setting the lpfc_log_verbose value to 0xffffffff might degrade system performance.

3.1.3 Creating a New Ramdisk Image

The elx_lpfc_install.sh script creates a ramdisk image containing the FC driver for the currently running kernel.

NOTE: You must create a new ramdisk image whenever the lpfc options in /etc/modprobe.conf are changed and

you want the change to take effect on the next reboot.

To create a new initial ramdisk image for inbox FC drivers and installed binary RPM FC driver kits, type:

dracut -f /boot/initramfs-<kernel-version>.img <kernel-version>

3.1.4 Dynamically Recognizing LUNs and Targets (Using Scan)

The FC driver enables you to dynamically recognize LUNs and targets without unloading or reloading the FC module and

without resetting the adapter.

To rescan an adapter’s targets with sysfs, given the adapter's host number (in this example, 3), type:

echo "- - -" > /sys/class/scsi_host/host3/scan

To limit the rescan to a particular target, given the adapter's host number (in this example, 3) and the target number (in this

example, 2), type:

echo "- 2 -" > /sys/class/scsi_host/host3/scan

You can also use the lun_scan script in the /usr/sbin/lpfc directory.