Physical adapters require a physical slot in a POWER system. Similarly, virtual adapters require a virtual slot. How the virtual slots of an LPAR are currently occupied can be shown with the help of the command “lpar lsvslot” (list virtual slots):

$ lpar lsvslot aix22
SLOT  REQ  ADAPTER_TYPE   STATE  DATA
0     Yes  serial/server  1      remote: (any)/any connect_status=unavailable hmc=1
1     Yes  serial/server  1      remote: (any)/any connect_status=unavailable hmc=1
5     No   eth            1      PVID=100 VLANS= ETHERNET0 1DC8DB485D1E
10    No   fc/client      1      remote: ms03-vio1(1)/5 c05076030aba0002,c05076030aba0003
20    No   fc/client      1      remote: ms03-vio2(2)/4 c05076030aba0000,c05076030aba0001
$

In the virtual slots 0 and 1 there are two virtual serial adapters, these are automatically created by PowerVM for each LPAR. Slots 2 to 4 are not used and therefore do not appear in the output. In slot 5 there is a virtual Ethernet adapter with the port VLAN ID 100, connected to the virtual Ethernet switch ETHERNET0. A virtual FC client adapter is located in each of the slots 10 and 20. The associated virtual FC server adapters are located on the virtual I/O servers ms03-vio1 in slot 5 and ms03-vio2 in slot 4. The primary and secondary WWPN of the virtual FC client adapter are also shown.

The maximum number of virtual slots an LPAR can have, is stored in the profile of the LPAR and can be shown using “lpar lsattr” (list attributes) and specifying the profile name:

$ lpar -p standard lsattr aix22
                     AUTO   BOOT  POWER   MAX    AFFINITY  WORK 
LPAR_NAME  NAME      START  MODE  CTRL   VSLOTS  GROUP     GROUP
aix22      standard  0      norm  none   30      none      none
$

The LPAR aix22 has 30 virtual slots. The number of virtual slots cannot be changed dynamically. The number can only be changed in the profile and the change will only take effect the next time the LPAR is activated by specifying the profile name. The attribute is max_virtual_slots and can be changed in the profile with the command “lpar chattr” (change attributes):

$ lpar -p standard chattr aix22 max_virtual_slots=40
$