Below is the solution from the Novell website :

5.10 Scanning for New Devices without Rebooting
If your system has already been configured for multipathing and you later need to add more storage to the SAN, use the following procedure to scan the devices and make them available to multipathing without rebooting the system.

1. On the storage subsystem, use the vendor¿s tools to allocate the device and update its access control settings to allow the Linux system access to the new storage. Refer to the vendor¿s documentation for details.

2. On the Linux system, scan the SAN at a low level to discover the new devices. At a terminal console prompt, enter

echo 1 > /sys/class/fc_host/host /issue_lip
For example, to probe the HBA on host1, enter

echo 1 > /sys/class/fc_host/host1/issue_lip
At this point, the newly added device is not known to the higher layers of the Linux kernel's SCSI subsystem and is not yet usable.

3.Scan all targets for a host to make its new device known to the middle layer of the Linux kernel's SCSI subsystem. At a terminal console prompt, enter

echo "- - -" > /sys/class/scsi_host/host /scan
For example, to probe the HBA on host1, enter

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

4.Check for scanning progress in the system log (the /var/log/messages file). At a terminal console prompt, enter

tail -30 /var/log/messages
This command displays the last 30 lines of the log. For example:

# tail -30 /var/log/messages
. . .
Feb 14 01:03 kernel: SCSI device sde: 81920000
Feb 14 01:03 kernel: SCSI device sdf: 81920000
Feb 14 01:03 multipathd: sde: path checker registered
Feb 14 01:03 multipathd: sdf: path checker registered
Feb 14 01:03 multipathd: mpath4: event checker started
Feb 14 01:03 multipathd: mpath5: event checker started
Feb 14 01:03:multipathd: mpath4: remaining active paths: 1
Feb 14 01:03 multipathd: mpath5: remaining active paths: 1

5. Repeat Step 2 through Step 4 to add paths through other HBA adapters on the Linux system that are connected to the new device.

6. Run the multipath command to recognize the devices for DM-MP configuration. At a terminal console prompt, enter

multipath
You can now configure the new device for multipathing.



Also refer to the following link :

http://www.novell.com/documentation/sles10/stor_evms/?page=/documentation/sles10/stor_evms/data/scandev.html


Regards
Pierluca

Thank you,

My systems is Suse Linux Enterprise 10. I probe with command modprobe -r hba and modprobe hba, but don't see the LUN.

Please follow the procedure I posted before , modprobrobe can't be use because is for load the modules and the modules of the HBA is all ready loaded .

The purpose of the procedure posted is to issue a LIP from the HBA to force the driver to rediscover the target devices.

Regards
Pierluca

Message was edited by:
chiodp

thank you for your time. I will try these procedure today.

Other consult. There is one utility from the qlogic website "Dynamic TGT-LUN Discovery utility" for scanning new added LUN. Can it see new LUN without reboot the server?.

thank you very much

thank you