directory. In old RHEL host you will not be getting this listing. In this case you can use
the /sys/class/scsi_host directory but it will list all internal adapters too.1. In Order to scan New Lun we need to run LIP (Loop Initialization Protocol) on the
interconnect to update the scsi layer to reflect the devices currently on the bus. LIP, is a
bus reset which cause the device addition and removal.
# ls -l /sys/class/fc_host
total 0
drwxr-xr-x 3 root root 0 Feb 27 09:11 host0
drwxr-xr-x 3 root root 0 Feb 27 09:11 host1
2. Make the OS aware of the new storage
#echo “1” > /sys/class/fc_host/host1/issue_lip
#echo “1” > /sys/class/fc_host/host2/issue_lip
#echo “- – -” > /sys/class/scsi_host/host1/scan
#echo “- – -” > /sys/class/scsi_host/host2/scan
Linux detecting SAN LUN without reboot
Detecting SAN LUN without rebooting the server in Linux
Rescan the bus by echoing the /sys filesystem (only for Linux 2.6 kernels)
For Linux 2.6 kernels only, a rescan can be triggered through the /sys interface without having to unload the host adapter driver or reboot the system. The following command will scan all channels, targets, and LUNs on host H.
echo “- – -” > /sys/class/scsi_host/host_H/scan
Example:
echo “- – -” > /sys/class/scsi_host/host1/scan
echo “- – -” > /sys/class/scsi_host/hos2/scan
echo “- – -” > /sys/class/scsi_host/hos4/scan
echo “- – -” > /sys/class/scsi_host/hos4/scan
OR
for host in `ls /sys/class/scsi_host/`;do
echo “- – -” >/sys/class/scsi_host/${host}/scan
done
Note: Below is the explanation about wild card ..
“- – -” in the above means C T L[“Channel on HBA” “Target SCSI id” “Lun”]
“- – -” is a wild card instead of specifying the C T L.
3. After rescanning, confirm whether you are seeing the new storage disks LUN] by listing the
content under proc
# cat /proc/scsi/scsi | grep scsi | uniq
4. Now we can list the newly scanned LUN using ????fdisk -l???? command.
# fdisk -l
5. If we have multipath configured then we can see as below:
# multipath
# multipath -ll
Recent Comments