Presenting Fibre-Channel Storage to AIX LPARs with Dual VIOS (NPIV / vFC)

Present SAN LUNs to AIX LPARs using NPIV / virtual Fibre Channel (vFC) so each LPAR has redundant SAN paths through two VIOS servers (VIOS1 = primary, VIOS2 = backup) and can use multipathing (native MPIO or PowerPath).

NPIV (N_Port ID Virtualization) lets an LPAR present its own virtual WWPNs to the SAN while physical Fibre Channel hardware is on the VIOS. With two VIOS nodes and dual SAN fabrics, you get end-to-end redundancy:

• VIOS1 and VIOS2 each present vFC adapters to the LPAR via the HMC.
• Each VIOS has physical FC ports connected to redundant SAN switches/fabrics.
• LUNs are zoned and masked to VIOS WWPNs. AIX LPARs discover LUNs, use multipathing, and survive single-path failures.

Prerequisites & Assumptions:

• HMC admin, VIOS (padmin/root), and AIX root access available.
• VIOS1 & VIOS2 installed, registered with HMC and reachable.
• Each VIOS has at least one physical FC port (e.g., fcs0, fcs1).
• SAN team will perform zoning & LUN masking.
• Backups of VIOS and HMC configs completed.
• You know which LPARs should receive which LUNs.

High-Level Flow:

• Collect physical FC adapter names & WWPNs from VIOS1 and VIOS2.
• Provide WWPNs to SAN admin for zoning & LUN masking.
• Create vFC adapters for each AIX LPAR on the HMC and map them across VIOS1/VIOS2.
• Verify mappings on HMC and VIOS (lsmap).
• Ensure VIOS physical FC ports are logged into fabric.
• On AIX LPARs: run cfgmgr, enable multipathing, create PVs/VGs/LVs as required.
• Test failover by disabling a path and verifying I/O continues.
• Document and monitor.

Step-by-Step Configuration

Step 1 — Verify VIOS Physical Fibre Channel Adapters
On VIOS1 and VIOS2, log in as padmin and identify FC adapters:
$ lsdev -type adapter
Expected output snippet:
VIOS1:
fcs0 Available 00-00 Fibre Channel Adapter
fcs1 Available 00-01 Fibre Channel Adapter
VIOS2:
fcs0 Available 00-00 Fibre Channel Adapter
fcs1 Available 00-01 Fibre Channel Adapter
Retrieve WWPNs for each adapter:
$ lsattr -El fcs0 | grep -i wwpn
Record results: 
VIOS    Adapter        WWPN
VIOS1   fcs0              20:00:00:AA:AA:AA
VIOS2   fcs0              20:00:00:CC:CC:CC

Step 2 — SAN Zoning & LUN Presentation
Provide the recorded VIOS WWPNs to the SAN Administrator.
Request:

• Zoning between each VIOS WWPN and Storage Controller ports.
• LUN masking to present LUN-100 to both VIOS WWPNs.
• Confirmation that both VIOS ports see the LUNs across both fabrics.

Tip: Ensure both fabrics (A & B) are zoned independently for redundancy.

Step 3 — Create Virtual Fibre Channel (vFC) Adapters via HMC
On the HMC:
Select AIX-LPAR1 → Configuration → Virtual Adapters.
Click Add → Virtual Fibre Channel Adapter.
Create two vFC adapters:
vfc0 mapped to VIOS1
vfc1 mapped to VIOS2
Save configuration and activate (Dynamic LPAR operation if supported).
Expected vFC mapping:
Adapter     Client LPAR    Server VIOS       Mapping Status
vfc0           AIX-LPAR1     VIOS1                Mapped OK
vfc1           AIX-LPAR1     VIOS2                Mapped OK

Step 4 — Verify vFC Mapping on VIOS
Log in to each VIOS (padmin):
$ lsmap -all -type fcs

Example output:
On VIOS1:
Name Physloc ClntID ClntName ClntOS
------------- ---------------------------------- ------ ----------- --------
vfchost0 U9105.22A.XXXXXX-V1-C5 5 AIX-LPAR1 AIX
Status:LOGGED_IN
FC name:fcs0
Ports logged in: 2
VFC client name: fcs0
VFC client WWPN: 10:00:00:11:22:33:44:55

On VIOS2:

Name Physloc ClntID ClntName ClntOS

------------- ---------------------------------- ------ ----------- --------
vfchost0 U9105.22A.XXXXXX-V2-C6 5 AIX-LPAR1 AIX
Status:LOGGED_IN
FC name:fcs0
Ports logged in: 2
VFC client name: fcs1
VFC client WWPN: 10:00:00:55:66:77:88:99

Confirm each VIOS vFC host maps to the correct AIX vFC client.

Step 5 — Verify VIOS FC Port Fabric Login
On each VIOS:
$ fcstat fcs0
Verify:
Port is online.
Logged into fabric.
No link errors.

Step 6 — Discover Devices on AIX LPAR
Boot or activate AIX-LPAR1 SMS mode and 

• Open HMC → Open vterm/console for AIX-LPAR1.
• HMC GUI: Tasks → Operations → Activate → Advanced → Boot Mode = SMS → Activate. 
• In SMS console: 5 (Select Boot Options) → Select Install/Boot Device → List all Devices → pick device → Normal Boot Mode → Yes to exit and boot from that device.

Verify Fibre Channel adapters:
# lsdev -Cc adapter | grep fcs
fcs0 Available Fibre Channel Adapter
fcs1 Available Fibre Channel Adapter
List discovered disks:
# lsdev -Cc disk
# lspv
Expected:
hdisk12 Available 00-08-00-4,0 16 Bit LUNZ Disk Drive

Step 7 — Configure Multipathing
If using native AIX MPIO, verify:
# lspath
Enabled hdisk12 fscsi0
Enabled hdisk12 fscsi1
If using EMC PowerPath:
# powermt display dev=all
Confirm both paths active.

Step 8 — Test Redundancy / Failover
To validate multipathing:
On VIOS1, disable the FC port temporarily:
$ rmdev -l fcs0 -R
On AIX LPAR, verify disk is still accessible:
# lspath -l hdisk12
Expected:
Enabled hdisk12 fscsi1
Failed hdisk12 fscsi0
Re-enable path:
$ cfgdev
Confirm path restoration:
Enabled hdisk12 fscsi0
Enabled hdisk12 fscsi1

Step 9— Post-Deployment Checks

Verify all paths:
# lspath
Check VIOS logs for FC errors:
$ errlog -ls
Save configuration backups:
$ backupios -file /home/padmin/vios1_bkup
$ backupios -file /home/padmin/vios2_bkup