HP-UX vPars and Integrity VM V6.1.5 Administrator Guide (5900-2295, April 2013)

The asynchronous event generation occurs in addition to any notifications issued using the SCSI
programming model, such as CHECK CONDITION on a subsequent I/O.
When the AVIO storage driver on the vPar/VM detects the events, it takes the appropriate actions,
such as discovering the new targets. For example, if new targets are added using the hpvmmodify
-a command, then the vPar/VM driver automatically detects the new device without the manual
scan. The vPar/VM automatically detects any modification of the underlying backing storage.
Changing the underlying backing storage of a vPar/VM is best done when it is not running to
avoid damaging it. If the change is to a running vPar/VM, the administrator is responsible for
knowing that the change will not adversely affect the health of the running environment. Although
HP-UX vPars and Integrity VM does check to determine if the device is in use, those checks are not
100% reliable, because the vPar/VM might or might not be using the device at the time it is
checked.
Backing storage can be adversely affected if the actual storage or access path is modified directly
by an HP-UX server command, for example, by removing a file backing store or unmounting the
file system. If the devices being changed are a result of some SAN reconfiguration, the ioscan
command should be run on the VSP before attempting the change with the hpvmmodify command.
If the backing storage is changed by remapping a different wwid to an existing dsf using:
scsimgr replace_wwid -D dsf, the hpvmdevmgmt -I command needs to be run. If the
backing storage is SAN presented as a different device and the change is done using:
io_redirect_dsf -d old_dsf -n new_dsf, the vPar/VM must be modified using the
hpvmmodify command to reference the new disk in place of the old disk.
1.7.2 Using direct I/O networking
The direct I/O networking feature supported in vPars and Integrity VM V6.1.5 allows administrators
to assign network ports directly to a vPar/VM, giving the vPar/VM direct and exclusive access to
that port on the NIC. NIC ports that are configured to be used for direct I/O are not shareable
and cannot be used to back a vswitch. Before a NIC port/card can be assigned to a vPar/VM,
you must first add it to the DIO pool.
NICs that support direct I/O networking on HP Integrity i2 and Superdome 2 servers provide either
Function Level Assignment (FLA) or Device Level Assignment (DLA). The function in FLA refers to a
single function on a multi-function NIC. A function can be a a single port on a multi-port card;
some cards support multiple functions on a single port. The device in DLA refers to the entire
multi-port NIC (all functions of the NIC). If a card supports FLA, each function (port) can be
individually added or removed from the DIO Pool. FLA functions (ports) can be individually assigned
to vPars/VMs. Each FLA function of the same card can be used by different vPars/VMs at the same
time.
If a NIC supports only DLA, the entire card is added or removed from the DIO pool. You cannot
assign a single port/function of a DLA card to the DIO pool. Once a DLA card is added to the
DIO pool, individual functions can be assigned to vPars/VMs. To assign different functions of a
DLA card to multiple vPars/VMs, each vPar/VM cannot be configured to ‘reserve’ resources
(resources_reserved setting); however if multiple vPars/VMs have been assigned functions
on the same DLA card (no reserved resources), only one VM can be booted at a time. For example:
• If you assign all four ports/functions of an FLA card to the DIO pool, you can assign port1 to
vPar1, port2 to vPar2, and boot both vPar1 and vPart2 at the same time.
• If you assign a DLA NIC with four ports to the DIO pool, you can assign port1 to vm1 and
port2 to vm2 only if resources_reserved is set to false. But you will only be able to boot
vm1 or vm2; they cannot be booted at the same time.
The direct I/O networking functionality provides the following:
• 10 GB Ethernet network functions
• Support for FlexNICs created by HP Virtual Connect
1.7 Types of I/O 19