Installing and Managing HP-UX Virtual Partitions (A.02.01)

How vPars Works
Virtual Consoles
Chapter 2 41
Virtual Consoles
HP-UX servers have a special terminal or window called a console that
allows special control and displays system error messages. Because
servers have a limited number of PCI slots, you may not want to allocate
one serial port for use as a console port for each partition you create.
With vPars, each virtual partition has its own virtual console. For each
partition, its console I/O is sent to its vcn (Virtual CoNsole) driver. From
the vcn driver, the console I/O is sent to the monitor. From the monitor,
the console I/O is sent to the vcs (virtual console slave) driver of the
partition that owns the hardware console port. Finally, the vcs driver
sends the console I/O to the physical hardware console. It is this vcs
driver that manages the console I/O to the actual hardware console port.
When the partition that owns the hardware console port is not running,
the vPars monitor takes over the management of the I/O to the hardware
console port, so you will still have access to the virtual console displays.
You can access the console port as you would on any non-vPars server, for
example, through a dumb terminal or lan console. Then, to cycle between
the virtual console displays of the various partitions, press Ctrl-A.
Each virtual partition has an 8K circular buffer for console output. If not
already displayed, the monitor copies this 8K buffer to the console when
you press Ctrl-A.
NOTE Note the following when using virtual consoles:
• Active Console I/O when Multiple Virtual Partitions are Booted
It is not deterministic which virtual partition will be active with the
physical console when multiple virtual partitions are booted.
• Switchover Pause with Shutting Down
When the virtual partition that owns the hardware console port is
shut down, there will be a pause of console output (the system is not
hung) as console I/O management switches over from the virtual
partition to the vPars monitor. Console output resumes
automatically after the pause. You will not lose any console output.
During the switchover period, no console input is accepted.