HP-UX vPars and Integrity VM V6.3 Administrator Guide

5.1.3 Dynamically changing the entitlements
While you cannot add or remove CPUs to and from a VM guest dynamically, you can change the
vCPU entitlement of the vCPUs that are already configured. You can use the hpvmmodify command
to change the entitlement.
5.1.4 Transforming VM guest to a vPar
For better guest performance, you can transform a VM guest offline to a vPar. Use the hpvmmodify
-x vm_type=vpar command to transform a VM guest to a vPar. For more information about
transforming VM guest to a vPar, see Section 13.5 (page 221).
5.1.5 Hyperthreading for VM guest
Hyperthreading is not supported for VMs. Therefore, individual VMs will not show any
hyperthreading capability. Even if hyperthreading and the lcpu_attr tunable are turned ON in
the VSP, the number of vCPUs in a VM cannot be more than the number of physical CPU-cores on
the system.
5.1.6 MCAs on VM guests
MCA’s (Machine Check Abort's) are the highest priority interruptions among a class of Itanium
processor interruptions.
They indicate an unexpected hardware condition where one or more processors need immediate
intervention to normal operation. Based on the scope and severity of the problem MCA's are
categorized into several categories.
Scope of an MCA
When observed problems can be isolated to a single processor, the MCA is categorized
as local. In some situations, it is possible for multiple processors to encounter local MCA's
simultaneously.
MCA’s caused by problems which affect the entire system are termed as Global MCA’s.
Severity of an MCA
When an MCA is encountered, Itanium processor hardware, system hardware, and system
software work together to isolate and if possible, correct the error so that the normal operations
can be resumed. Based on the success of this operation, MCA’s are termed as
Recoverable
The faulty code is either corrected or terminated; system operation is resumed.
OR
Non-recoverable
Normal system operation cannot be safely continued; further actions depend on the exact
nature of the problem. The system will be rebooted.
All the four combinations of these are possible.
Integrity VMs work with emulated virtual Itanium processors (vCPUs). Consequently, all error
conditions that such virtual processors encounter are handled by the Virtual Machine Monitor.
MCAs encountered by emulated vCPUs are always categorized as non-recoverable; the VM is
rebooted and necessary log files are generated.
If such a problem is encountered, you must gather diagnostic data and contact HP Support. For
more information, see Appendix B (page 275).
54 CPU and Memory