Linux Edu Handbook

Script:

    # ls /sys/class/fc_host

     host0  host1  host2  host3

     fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l

     echo "1" > /sys/class/fc_host/host0/issue_lip

     echo "- - -" > /sys/class/scsi_host/host0/scan

     echo "1" > /sys/class/fc_host/host1/issue_lip

     echo "- - -" > /sys/class/scsi_host/host1/scan

     echo "1" > /sys/class/fc_host/host2/issue_lip

     echo "- - -" > /sys/class/scsi_host/host2/scan

     echo "1" > /sys/class/fc_host/host3/issue_lip

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

     cat /proc/scsi/scsi | egrep -i 'Host:' | wc -l

     fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l

or run rescan-scsi-bus.sh script from RHEL.

To scan new LUNs - QLogic driver:

You need to find out driver proc file /proc/scsi/qlaXXX.

For example on my system it is /proc/scsi/qla2300/0

Once file is identified you need to type following command (login as the root):

# echo “scsi-qlascan” > /proc/scsi/qla2300/0 # cat /proc/scsi/qla2300/0

Now use the script rescan-scsi-bus.sh new LUN as a device. Run script as follows:

# ./rescan-scsi-bus.sh -l -w

The output of ls -l /sys/block/*/device should give you an idea about how each device is connected to the system.