Introducing HP-UX 11i Virtual Partitions

Sep 2007 12
invoked. In fact, the monitor is invoked only when HP-UX makes calls to firmware, or when the OS
is shutting down, or when vPars management commands are executed.
On Integrity based systems, the underlying firmware is virtual partition aware and a significant
portion of the monitor functionality is performed in firmware.
vPars Database (vpdb)
At the heart of the monitor is the partition database, which tracks the resources that are associated
with each vPar. The database is created by the user using vpar commands and contains the
resource ownership details of individual vPars. When the vPar monitor is running, the master copy
of this database is maintained in memory by the monitor. Changes to vPars configuration through
the use of vPar commands are first verified by the monitor, then applied to the database in memory.
This in-memory database is then written out to the database copies on the boot disks of running
vPars. Because the database is stored on disk, all changes to the partition database are preserved
across system reboots.
vPars Commands
Changes to the vPars configuration are made using a special set of commands. These commands
modify the database in memory, which is synchronized with all of the vPar databases on disk and
preserved across reboots. The commands can be issued from any of the active vPars, provided
appropriate user permission is granted.
A few of the key commands are as follows:
Command
Description
vparcreate
create a vPar, assigning CPU, memory and I/O resources to it.
vparremove
destroy a vPar, where the partition definition is removed and all resources
associated with the given vPar are reclaimed by monitor
vparmodify
add or modifies resources or attributes of an existing vPar
vparboot
start/boot a vPar
vparreset
stop/reset a vPar
vparstatus
display information about one or more vPars
vPars Kernel Component
The vPars product contains a kernel component that assists the vPars monitor in sharing platform
resources across vPars and provides a channel for communication between vPars commands and
the monitor. The same kernel can be used to boot a standalone system. The vPar kernel
component only gets enabled when the kernel is running inside a vPar.