REDAIX - Unix(Red Hat & IBM AIX) | Cloud & DevOps

A new LPAR was created and new virtual fibre channel adapters were presented to both VIO servers using DLPAR. Now, it’s time to map the newly created virtual fibre channel adapter to a physical fibre channel adapter. But which vfchost device to map? What are checks needed to be done? I’ll step you through the process of mapping NPIV virtual fibre channel adapter to a physical adapter on the VIO server. Check Your Virtual Adapter (vfchost) In this example, I have performed a DLPAR of virtual fibre channel adapter with the ID 38 on both the VIO servers. We now need to identify the vfchost device presented to the VIO server in order to be able to map them later. Use the lsdev command with the –slots flag in the VIO restricted shell. 

NPIV (Virtual Fibre Channel Adapter) With NPIV, you can configure the managed system so that multiple logical partitions can access independent physical storage through the same physical fibre channel adapter. (NPIV means N_Port ID Virtualization. N_Port ID is a storage term, for node port ID, to identify ports on the nod (FC Adpater) in the SAN area.) To access physical storage in a typical storage area network (SAN) that uses fibre channel, the physical storage is mapped to logical units (LUNs) and the LUNs are mapped to the ports of physical fibre channel adapters. Each physical port on each physical fibre channel adapter is identified using one worldwide port name (WWPN). NPIV is a standard technology for fibre channel networks that enables you to connect multiple logical partitions to one physical port of a physical fibre channel adapter. Each logical partition is identified by a unique WWPN, which means that you can connect each logical partition to independent

How to scan the new LUN in AIX and RHEL? For AIX: Make sure you are taking the below output before scan for new lun/disk. #lspv #lspv|wc -l Now execute the below commands to scan the new lun/disk. #cfgmgr check the new lun/disk added to the box with the help of new outputs of the following compared with the old output. #lspv #lspv|wc -l For RHEL Linux: Make sure you are taking the following output before scan for new lun. (Knowing the newly added Lun size before we scan would be better) fdisk -l cat /proc/scsi/scsi cat /proc/scsi/scsi|grep -i host|wc -l multipath -l tail -50 /var/log/messages Now execute the below commands to scan the new lun. syntax:       echo "- - -" > /sys/class/scsi_host/host(n)/scan                     #echo "- - - " > /sys/class/scsi_host/host0/scan (Make sure the space is there between the hyphen in the echo command [ echo "- - -" ]  and  you should do this for all HBAs. check the new lu