Linux WWPN and adding SAN disk

To rescan an entire SCSI bus and re-register all devices found:

When dealing with fibre attached storage, it is necessary to issue a LIP (loop initialization primitive) on the fabric:
shell> echo "1" > /sys/class/fc_host/host#/issue_lip

Replace the “#” with the number of the SCSI bus to be rescanned.

Note: Issueing a LIP (above) on Red Hat Enterprise Linux 5 is all that is needed to rescan fibre attached storage. Once the LIP is issued, the bus scan may take a few seconds to complete.

To rescan all other SCSI attached storage, a rescan should be issued:

shell> echo "- - -" > /sys/class/scsi_host/host#/scan

Replace the “#” with the number of the SCSI bus to be rescanned.

In addition to re-scanning the entire bus, a specific device can be added or deleted for some versions or Red Hat Enterprise Linux as specified below.


To remove a single existing device explicitly
shell> echo 1 > /sys/block//device/delete



OR, use the rescan-scsi-bus.sh under sg3-utils.rpm


To see the WWPN:

at BIOS : CTRL-Q Fast Util

at OS : qlogic : /proc/scsi/qlxxxx
emulex : /sys/class/scsi/device/driver/...../portid