N-port Virtualization(NPIV)

through NPIV partitions of managed systems  can access the SAN storage directly through the same physical fibre channel adapter.

ex...
         suppose you have assigned 200 GB storage to vio server.this  200GB storage you can assign to the  logical partitions through mapping lv, pv  to the scsi adapters of the particular partitions. what happens when a  single LPAR needs  100GB  and there is only 50 GB storage left in VIO Server partition.
                                               .again you have to assign a LUN to VIO Server and then  you have to create  lv to provide the more,space. this can be tough  and time-taking if many server's are there. for reducing this over head NPIV was introduced through which we can directly assign the storage to the partitions.


 SAN  ------------->  LUN -------------->MAPPED TO THE PORT OF PHYSICAL FC ADAPTER





* Each virtual fibre channel adapter on each client logical partition receives a pair of unique WWPNs. The client logical partition uses one WWPN to log into the SAN at any given time. The other WWPN is used when you move the client logical partition to another managed system.

*Using their unique WWPNs and the virtual fibre channel connections to the physical fibre channel adapter, the operating systems that run in the client logical partitions discover, instantiate, and manage their physical storage located on the SAN


To enable N_Port ID Virtualization (NPIV) on the managed system, you create the required virtual fibre channel adapters and connections as follows:
1.using HMC  create virtual fibre channel adapters on the VIO Server logical partition and map  them  with virtual fibre channel adapters on the client logical partitions.

 2..When you create a virtual fibre channel adapter on a client logical partition, the HMC generates a pair of unique WWPNs for the client virtual fibre channel adapter.this you can see through HMC by viewing the properties of client FC adapter.

 3. we need to check whether the HBA port is connected to the SAN switch on which NPIV  is enabled.
that that we run $lsnport command on vio server.


 if fabric parameter is "1" . then NPIV is supported
 if it is "0" it means NPIV is not supported.

$lsnports


name             physloc                fabric 
fcs0              ---                          1
fcs1              ---                          1
fcs2              ---                           1


here fabric parameter is set to"1". that means NPIV is supported and we can do mapping.

now check the virtual FC adapter on the vio server that you have created

$lsdev  -vpd|grep vfchost
vfchost0  
vfchost1

for mapping the virtual FC adapter to physical FC adapter use the "vfcmap" command

$vfcmap -vadapter vfchost1   -fcp  fcs1

to check that mapping has been done correctly and the clients are able to login to the SAN.

#lsmap -vadapter vfchost1 -npiv