Determining the Size of a Physical Volume

There are a number of different ways to determine the size of a physical volume (disk, LUN) under AIX.

If you have root privileges, you can use the bootinfo command with the “-s” (size) option:

#  bootinfo -s hdisk0

The size of the physical volume is given in MB. In the example 51,200 MB or about 50 GB.

Without root privileges, the getconf command can be used. With this command, system-wide configuration parameters as well as device-specific variables can be displayed. The device-specific variable DISK_SIZE can be used to display the size of a physical volume. The physical volume in question is specified by the absolute path of the physical volume’s block or character device file:

$ getconf DISK_SIZE /dev/hdisk0

Here, too, the size is given in MB.

Another option, which again requires root privileges, is to use the lsmpio command. The command offers the option “-q” (query) to display data about an MPIO storage device:

# lsmpio -ql hdisk0
Device:  hdisk0
           Capacity:  50.00GiB

The size is directly displayed in GB (GiB) this time.

If the physical volume is part of a volume group, the lspv command can also be used to at least estimate the size:

$ lspv hdisk0
TOTAL PPs:          199 (50944 megabytes)    VG DESCRIPTORS:   2

The area that can be used for data is specified here (50,944 MB), the physical volume itself is somewhat larger, since space is also used for administrative information.

Adding Logical SR-IOV Ports

SR-IOV Ethernet port with internal switch and 3 logical ports.

In order that an LPAR can use a virtual function of an SR-IOV adapter in PowerVM, a so-called logical port must be created for the LPAR. Which logical ports already exist can be displayed with the command “ms lssriov” and the option “-l” (logical port):

$ ms lssriov -l ms03

Since the SR-IOV adapters have just been configured to shared mode, there are of course no logical ports yet. To add a logical SR-IOV port to an LPAR, the command “lpar addsriov” (add SR-IOV logical port) is used. In addition to the LPAR, the adapter ID and the port ID of the physical port must be specified. Alternatively, a unique suffix of the physical location code of the physical port can also be specified:

$ lpar addsriov aix22 P1-C11-T1

The creation can take a few seconds. A quick check shows that a logical port has actually been created:

$ ms lssriov -l ms03
U78AA.001.VYRGU0Q-P1-C11-T1-S1  1        0      27004001  aix22  2.0       a1b586737e00   -

Similar to a managed system for virtual Ethernet, an internal switch is implemented on the SR-IOV adapters for each physical Ethernet port, see figure above. One of the virtual functions is assigned to each logical port. The associated LPARs access the logical ports directly via the PCI Express bus (PCIe switch).

An LPAR can easily have several logical SR-IOV ports. With the command “lpar lssriov” (list SR-IOV logical ports) all logical ports of an LPAR can be displayed:

$ lpar lssriov aix22
27004001  Yes  1        0      0          2.0       100.0         0     all    a1b586737e00   -

There are a number of attributes that can be specified for a logical port when it is created. Among other things, the following properties can be configured:

    • capacity – the guaranteed capacity for the logical port.
    • port_vlan_id – the VLAN ID for untagged packets or 0 to switch off VLAN tagging.
    • promisc_mode – switch promiscuous mode on or off.

The complete list of attributes and their possible values can be found in the online help (“lpar help addsriov“).

As an example we add another logical port with port VLAN-ID 55 and a capacity of 20% to the LPAR aix22:

$ lpar addsriov aix22 P1-C4-T2 port_vlan_id=55 capacity=20

The generated logical port thus has a guaranteed share of 20% of the bandwidth of the physical port P1-C4-T2! The LPAR now has 2 logical SR-IOV ports:

$ lpar lssriov aix22
27004001  Yes  1        0      0          2.0       100.0         0     all    a1b586737e00   -
2700c003  Yes  3        2      1          20.0      100.0         55    all    a1b586737e01   -

After the logical ports have been added to the LPAR using the PowerVM Hypervisor, they appear in the Defined state. The logical ports appear under AIX as ent devices, like all other Ethernet adapters!

aix22 # lsdev -l ent\*
ent0 Available       Virtual I/O Ethernet Adapter (l-lan)
ent1 Defined   00-00 PCIe2 10GbE SFP+ SR 4-port Converged Network Adapter VF (df1028e214100f04)
ent2 Defined   01-00 PCIe2 100/1000 Base-TX 4-port Converged Network Adapter VF (df1028e214103c04)
aix22 #

After the config manager cfgmgr has run, the new ent devices are in the Available state and can be used in exactly the same way as all other Ethernet adapters.

7.6. SR-IOV

7.6.1. Activating Shared Modes

7.6.2. Configuration of Physical SR-IOV Ports

7.6.3. Adding Logical SR-IOV Ports

7.6.4. Changing a Logical SR-IOV Port

7.6.5. Removing Logical SR-IOV Ports

7.6.6. Setting an SR-IOV Adapter from Shared back to Dedicated