Scan for new Lun(s) in AIX

After creating a Lun in a storage and mapping the new Lun to a AIX server you should list the current disks:

# vxdisk -e list
...

Then reconfigure devices using cfgmgr:

# cfgmgr
...

Scan for new Luns and list them again:

# vxdisk scandisks
# vxdisk -e list
...
stor01_18   auto:none   -   -   online   invalid   hdisk20   -

When you have mapped your new Lun right then you should note a difference between the first vxdisk -e list commend and the second vxdisk -e list command. From here you can do everything you need to do with the new Lun within Veritas.
Some other useful AIX based tools to check for new Luns (after running cfgmgr):

List configuration:

# lscfg -v | grep FC
  ...
  hdisk19        ...        MPIO IBM 2145 FC Disk
  hdisk20        ...        MPIO IBM 2145 FC Disk
  ...

List physical volumes:

# lspv
...
hdisk19         none                                VeritasVolumes
hdisk20         none                                None

List disk class based devices:

# lsdev -Cc disk
...
hdisk19 Available 07-00-02 MPIO IBM 2145 FC Disk
hdisk20 Available 07-00-02 MPIO IBM 2145 FC Disk