HP Integrity Virtual Machines 4.3: Release Notes (5900-2265, May 2012)

The command line interface for migrating VMs is still the same for VMs that include NPIV AVIO
devices. The hpvmmigrate command is used to perform both online and offline migration. To
migrate a guest VM1 from machine HostA to HostB, run the following command:
# hpvmmigrate -P VM1 -h HostB
To perform online migration, use the -o option:
# hpvmmigrate -o -P VM1 -h HostB
If hpvmmigrate cannot find a matching PFC on the target Host, it prints an error message stating
that the NPIV device has no match:
hpvmmigrate: ERROR (VM1): Remote message:
Device 0x50D1438FF62CBCD8,0x50D1438FF62CBCD9 has no match on this HPVM server.
If hpvmmigrate finds multiple matching PFCs on the target Host, it will choose the PFC with the
least number of HPVM NPIV entries, to balance the NPIV HBAs evenly among the PFCs. There are
some limitations to this approach. If a VM uses two NPIV HBAs for multi-pathing to the same LUNs,
after migration, there is no guarantee that the NPIV HBAs will be on separate PFCs. They could
end up configured on two ports of the same PFC.
9.2.2 Probe of NPIV HBAs for Fibre Channel Targets May Timeout
During online migration, the target VM Host probes any NPIV HBAs for Fibre Channel (FC) targets.
If this probe takes close to 30 seconds (or longer), online migration times out and aborts. The
hpvmmigrate command prints an error:
# hpvmmigrate -P guest -h host2 -o
...
hpvmmigrate: Frozen phase (step 23) - progress 21%
Target: (protocol low) header read timeout, 30 seconds
Target: could not receive message header
On the target VM Host machine, the syslog will contain the following warning message:
vmunix: HVSD: HPVM online migration warning: NPIV probe took too long, 79 seconds
To solve this problem, use the following workaround:
1. Verify that the probe time of each individual FC HBA is under 10 seconds.
2. On the target VM Host, run the ioscan command to measure how long each FC HBA takes
to probe. The ms_scan_time column gives the probe time.
# ioscan -P ms_scan_time -C fc
Class I H/W Path ms_scan_time
============================================
fc 0 44/0/0/0/0/0/0 0 min 7 sec 7 ms
fc 1 44/0/0/2/0/0/0 0 min 6 sec 213 ms
fc 2 44/0/0/2/0/0/1 0 min 4 sec 1 ms
3. If an individual FC HBA takes more than 10 seconds to probe, check your FC switch and zone
settings to see why the probe time is so high.
4. Increase the online migration timeout value using the hpvmmodify command. For example,
if the syslog reports a warning that the NPIV probe time is 79 seconds, increase the timeout
value several seconds beyond that, to around 90 seconds (90000 msec):
# hpvmmodify -P guest1 -x "tunables=ogmo=90000"
# hpvmmodify -P guest1 -x migrate_frozen_phase_timeout=90
The default timeout value for ogmo is 30000 msec (30 seconds). The default timeout value for
migrate_frozen_phase_timeout is 60 seconds.
Alternatively, you can also reduce the NPIV probe time by reducing the number of NPIV HBAs
assigned to the guest.
42 Migrating Virtual Machines