HP Integrity Virtual Machines Release Notes Version A.03.50

virtual network interface cards in the guest and any physical network interface cards in the VM
Host that are used by vswitches. When TSO is enabled, guest networks are interrupted.
To verify whether TSO is turned on, enter the following command:
# lanadmin -x vmtu n
Where n is the VM Host interface, as displayed by the hpvmnet command. For example, to verify
that TSO is on for lan0, enter the following command:
# lanadmin -x vmtu 0
Driver/Hardware supports TCP Segmentation Offload, Current VMTU = 32160
To turn TSO off on lan0, use the following command:
# lanadmin -X vmtu 0 0
Virtual MTU is set to 0
Note that this restriction applies to VIO interfaces.
7.12 Restarting Vswitches
It is necessary to restart the vswitch when:
• You replace the physical network card associated with the vswitch.
• You change a VM Host IP address associated with the vswitch's network interface card.
• You change the network interface characteristics on the VM Host; for example, by using the
lanadmin command to change checksum offloading (CKO).
• You notice that there is no communication from an avio_lan interface to a lan interface
after booting the guest(s) while the vswitch is down.
For information about how to restart vswitches, see the HP Integrity Virtual Machines Installation,
Configuration, and Administration manual.
When you restart a vswitch, it is not necessary to restart the guests using the vswitch.
7.13 Guest AVIO Interface Behavior
The following list describes the guest AVIO interface behavior when guest boots while vswitch
is down or resetting:
• If you boot a guest while the vswitch is not up, AVIO interfaces associated with the vswitch
might not be claimed in the guest. For example, this 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. If you encounter this problem, first fix the vswitch state (that is, ensure that hpvmnet
displays its state as Up), and then execute the ioscan command in the guest. These actions
will claim the AVIO interfaces.
• After ioscan claims the AVIO devices in the guest, you might notice that the AVIO devices
cannot communicate with another VIO guest interface configured on the same vswitch.
When this occurs, invoke the hpvmnet -r option on the vswitch to restore connectivity.
• If the vswitch is in an unstable state while the guest is booting, guest AVIO interfaces might
fail initialization and move to the DOWN state (as displayed by thelanscan command).
When this occurs, first ensure that the vswitch enters a stable state , then reset the guest
interface using lanadmin.
7.14 AVIO LAN Devices Not Claimed by Guest with DOWN Vswitch at
Boot Time
In addition to running ioscan, you must re-run the necessary network startup scripts, so that
IP addresses can be reconfigured on the network interface cards (NICs). For example:
/sbin/rc2.d/S340net start
/sbin/rc2.d/S340net-ipv6 start
7.12 Restarting Vswitches 57