Technical data

7.1.4 Using IP Alias Addresses in the Guest Not Supported for IPv4
Integrity VM Version 4.3 does not support the use of IP alias addressing in the guest for IPv4.
7.1.5 AVIO LAN Devices Left Unclaimed by OpenVMS Guest if vswitch is Down at
Boot
If you boot an OpenVMS guest while the vswitch is not UP, AVIO interfaces associated with the
vswitch might not be claimed in the guest. For example, this issue might occur if the guest is booted
prior to booting the vswitch, or if the corresponding network interface on the VM Host is not cabled
during the guest boot time.
If you encounter this problem, perform the following steps:
1. Fix the vswitch state; that is, ensure that the hpvmnet command displays the vswitch state as
UP.
2. Once the vswitch is started, reboot the OpenVMS guest to get the AVIO LAN devices
recognized, which ensures that all the AVIO LAN interfaces that are configured through this
vswitch are recognized by the guest.
7.1.6 Suspend and Resume During Guest Boot Might Cause Guest VIO LAN Problem
The suspend and resume operations during guest boot might cause the guest VIO lan not to operate.
In this case, the lanadmin command displays the Operation StatusOperation Status of a
guest VIO LAN as down.
Use the reset command in lanadmin to enable the guest VIO LAN to function properly.
7.1.7 Vswitch Use Disables TSO and CKO Capabilities on the IP Address on the
Backing LAN Interface
When a LAN interface has IP addresses configured and used by a vswitch, Integrity VM disables
the TSO and CKO capabilities on the interface’s IP addresses. Consequently, poorer than expected
performance is experienced from these IP addresses. However, the TSO and CKO capabilities
remain unchanged (enabled by default) in the VM Host’s and guest’s data-link layer, that is, the
traffic from guest AVIO LAN interfaces to the network is not being degraded by this feature.
Degradation is seen only on traffic destined to or sent from the VM Host.
Also, after a vswitch is halted, the TSO and CKO capabilities remain disabled on the IP addresses
of the backing LAN interface. Integrity VM does not restore these properties back to their original
states. To restore the TSO and CKO on the IP addresses, unconfigure the IP addresses and then
reconfigure them.
7.1.8 Vswitch Use Disables TSO and CKO Capabilities on IP Addresses and Online
VM Migration
Because Integrity VM disables the TSO and CKO capabilities on the LAN interface's IP address
(resulting in poorer than expected VM Host data-transfer performance) HP recommends that you
dedicate a LAN interface solely for Online VM Migration data transfer to improve data transfer
time. That is, to receive the best performance on host-to-remote data transfers on a LAN interface,
do not configure a vswitch over it.
7.1.9 Software LRO to be on by default on Host and Guest Interfaces
The newer 10 Gig cards have a new feature that allows the driver to combine TCP segments and
pass the combined packet to the upper layers. This new feature is known as Packet reassembly
(PR) or Large Receive Offload (LRO). The newer 10 Gig interfaces default to s/w LRO enabled as
of the HP–UX 11i v3 September 2011 release, resulting in much better inbound performance for
the VM Host. The HP–UX 11i v3 Marh 2011 versions of these drivers might also be capable of
s/w LRO and can be enabled with the nwmgr command:
28 Networking Information