Persistent naming – Dell Emulex Family of Adapters User Manual
Page 831

Emulex Drivers Version 10.2 for Linux User Manual
P010081-01A Rev. A
3. Configuration
FC and FCoE Driver Configuration
831
To create a new initial ramdisk image for inbox FC and FCoE drivers and installed
binary RPM FC driver kits:
For RHEL 5.x distributions, type
mkinitrd -f /boot/initrd-
For RHEL 6.x distributions, type
dracut -f /boot/initramfs-
Dynamically Recognizing LUNs and Targets (Using scan)
The FC and FCoE driver enables you to dynamically recognize LUNs and targets
without unloading or reloading the LPFC 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 Emulex lun_scan script in the /usr/sbin/lpfc directory.
Persistent Naming
The generic device manager for the Linux kernel is “udev”, which primarily manages
device nodes in the /dev directory.
Using udev to Discover Logical to Physical Mappings for
sd Devices
In Linux, the driver for SCSI disk drives is “sd”. A disk device name has an sd prefix.
Persistent names for sd devices are provided in the /dev/disk/by-id directory. To find
the persistent udev name for the disk, which is currently “sdc”, type
cd /dev/disk/by-id
ls -l | grep sdc
The sample output is:
lrwxrwxrwx 1 root root 9 2006-08-01 19:08 scsi-32000000c5005d6e6 -> ../../sdc
In the previous example, the disk has no partitions. If the disk had two partitions, the
output would look like the following:
lrwxrwxrwx 1 root root 9 2006-08-01 19:08 scsi-32000000c5005d6e6 -> ../../sdc
lrwxrwxrwx 1 root root 10 2006-08-01 19:08 scsi-32000000c5005d6e6-part1 -> ../../sdc1
lrwxrwxrwx 1 root root 10 2006-08-01 19:08 scsi-32000000c5005d6e6-part2 -> ../../sdc2