HP Integrity Virtual Machines 4.3: Installation, Configuration, Administration
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And location is a VM Host system file.
For complete information about constructing storage specifications for virtual machines, see
Section 6.2.2.1 (page 101).
The type of VM Host backing store can affect the performance of the virtual machine. Use the
ioscan command to obtain information about the current device configuration on the VM Host
system, and try to distribute the workload of the virtual machines across the physical backing
stores.
When you share a physical backing storage device among virtual machines. potential conflicts
are not always obvious. For example, if you use a file in a file system on /dev/disk/disk1 as
a backing store, the raw device (/dev/rdisk/disk1) cannot also be used as a backing store.
For more information about specifying virtual devices, see Chapter 6 (page 83).
Integrity VM checks the current physical configuration when you create a virtual machine using
the hpvmcreate command. If the virtual machine uses backing stores that are not available, the
virtual machine is created, and warning messages provide details. If you use the hpvmstart
command to start a virtual machine that requires physical resources that are not available on the
VM Host system, the virtual machine is not allowed to start, and error messages provide detailed
information about the problem.
After you create a virtual machine, you can use the hpvmmodify command to add, remove, or
modify storage devices for the virtual machine. To add a device to an existing virtual machine,
include the -a option, the same way you would on an hpvmcreate command. For example,
the following command modifies the virtual machine named host1, adding a virtual DVD
device backed by the physical disk device /c1t1d2. The virtual hardware address is omitted
and will be generated automatically.
# hpvmmodify -P host1 -a dvd:scsi::disk:/dev/rdisk/disk2
You can modify storage devices while the virtual machine is running. It is not necessary to restart
the virtual machine; however, it may be necessary to rescan for devices on the virtual machine.
Some devices should be restricted to use by the VM Host and to each guest (for example, boot
devices and swap devices). Specify restricted devices using the hpvmdevmgmt command. For
more information about sharing and restricting devices, see Section 8.12.2.4 (page 172).
Any alternate boot devices should be set with the same care that you would use on a physical
system. If the primary boot device fails for any reason, a virtual machine set to autoboot attempts
to boot from devices in the specified boot order until either an option succeeds or it reaches the
EFI Shell. Make sure that any specified boot options, and the boot order, are appropriate for the
guest. For more information about the autoboot setting, see Table 3-5.
NOTE: MPT virtual storage devices (VIO) have a maximum SCSI queue depth of 8. This is
sufficient for the default SCSI queue depth of all guest types that have applied their guest kits.
Increasing SCSI queue depths beyond the defaults might result in some I/O failures due to
exhaustion of guest I/O retries.
If the VM Host storage used by a virtual MPT adapter is slow due to hardware problems or
heavy I/O loads, the following HP-UX spinlock timeout might occur inside an HP-UX guest:
============== EVENT ============================ = Event #0 is CT_PANIC on CPU #2; = p crash_event_t
0xe000000100385000 = p rpb_t 0xe0000001011e4ff0 ============== EVENT ============================
RR0=0x00800831 RR1=0x00000831 RR2=0x02cd0031 RR3=0x02450031
RR4=0x03450031 RR5=0x00ffff31 RR6=0x07ff8031 RR7=0x00dead31
BSP SP IP
0xe000000200024810 0xe0000002000434f0 0xe000000001f3d7c0 panic+0x410
0xe0000002000247b8 0xe000000200043500 0xe000000001fa8320 too_much_time+0x380
pdk_spinlock.c:1619 wait_for_lock_spinner(inlined)
0xe0000002000246b8 0xe000000200043500 0xe000000000de4c80 wait_for_lock+0x670 0xe000000200024680 0xe000000200043570
0xe000000000d7d820 spinlock+0xe0
0xe000000200024628 0xe000000200043570 0xe000000000c61de0 fw_lock_acq+0x70
0xe0000002000245b8 0xe000000200043570 0xe000000000c61be0 sal_proc_real+0x100
54 Creating Virtual Machines