Reconfiguring vPars v6 memory with zero downtime
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WARNING
A very large increase in total memory using hpv m modify -r option will make oating memory value much larger
than base memory, resulting in a vPar panic during boot time. Note that -r option of h pv m m od ify(1M) command
is deprecated for modication of vPar memory conguration. You can use -a mem|-d mem|-m mem options of
hpv m m od ify(1M) command to modify memory of a vPar with the recommended base and oating memory values.
Monitoring the status of an online operation
The vparstatus command output (-v option) shows the status of the last initiated memory migration operation. In
the vparstatus output, this shows up under the section ”Memory OL* Details”.
The operation eld indicates what type of online migration event was initiated, and the status eld indicates the current
state of the operation. The status eld may contain PASS, PENDING, CANCELLED or FAIL. The pending status indicates
that the operation is in progress. If the status shows CANCELLED, it means the online memory migration was explicitly
cancelled by the user successfully. If the status shows FAILED, that means the operation failed to complete for some
reason. When this happens, there are two main logs on the vPar that the system administrator may consult to determine
what prevented the operation from completing successfully: the EVM event log (evmget | evmshow), and the operating
system log (/var/adm/syslog/syslog.log).
NOTE
There are some scenarios where online memory migration cannot be initiated. In such failure cases hpvmmodify
command will save the new memory changes in the “next” conguration le, which will be applied during the next boot
of the vPar, whereas vparmodify command does not save any memory changes that cannot be dynamically applied.
Cancelling an online memory migration operation
Memory migration, and in particular the memory delete operation, could sometimes take a long time to complete. This
is because for the memory delete operation, the kernel has to rst evacuate the contents of the memory pages that are
in use by applications. Depending on the size of the memory being deleted, its usage and the amount of memory that
is free, this operation could end up taking considerable time. The vparmodify command contains an option to allow the
user to cancel an ongoing memory migration. The option (-C ) will allow the user to cancel the last pending memory OL*
operation on a vPar. The operation can be cancelled under two conditions: the operation is still in the PENDING state and
the operating system has not committed to the operation. The status of the operation can be determined using output of
the vparstatus –v command. The progress of the operation can be determined using the output of the evmget |
evmshow command from within the vPar being modied.
Technical white paper | HP-UX vPars and Integrity VM v6.2