User manual

Quick VAX MP Installation Guide

First make sure you have VAX MP installed and have met requirements described above in section “Host

software requirements” appropriate for your host operating system.

The easiest way to install VAX MP is by downloading pre-built executable image for your host OS. If you

want to build VAX MP yourself, refer to Addendum A of this document (“Building VAX MP”).

For running VAX MP on 64-bit edition of Windows, we recommend to use 32-bit build of VAX MP, since it

is preliminary believed to have slightly better overall performance than x64 build, by few percent.

Default suggested mode for 64-bit Linux is the use of 64-bit VAX MP build. Use of 32-bit build of VAX MP

on 64-bit Linux is possible

and is straightforward for builds with NONET or NET options and without VDE.

However we have not benchmarked yet 32-bit build of VAX MP vs. 64-bit build when both are executed

under 64-bit Linux and cannot at this point definitively recommend using 32-bit build on 64-bit Linux.

Installation of 32-bit build of VAX MP built with SHR or VDE options (i.e. making use of 32-bit

libpcap

and/or VDE shared libraries) under 64-bit Linix may be possible as well, but is much more complicated and

had not been attempted or tested and is not recommended, and its description is beyond the scope of

this document.

For OS X only 64-bit build of VAX MP is provided.

You can either move your pre-existing OpenVMS installation to VAX MP or install OpenVMS under VAX

MP from scratch. No modifications to existing system disk image are required other than the installation

of VSMP tool in a separate directory on the OpenVMS system disk.

However we most strongly recommend using only MSCP disks (SIMH device name RQxxx) with VAX MP

instance intended to run in multiprocessor mode. Other types of virtual disks (RLxxx devices) can be

used in multiprocessor mode, but their performance will be inferior and they can also induce “choppy”

system behavior and poor responsiveness.

Therefore the use of non-MSCP disks for any significant IO

loads is strongly discouraged. If you have an existing system disk image on a non-MSCP device, transfer

it to an MSCP device first; and similarly for all data files on other disks you are planning to use. If you

plan on installing OpenVMS from scratch, install it only on MSCP (RQ) disk device.

If you have an existing system disk image you want to use with VAX MP, proceed to step 2. For new

installations, proceed to step 1.

After installing ia32 compatibility package, such as ia32-libs for Ubuntu or other Debian or Debian-like

editions of Linux. Refer to http://www.debian-administration.org/articles/531 and http://www.debian-

administration.org/articles/534.

Non-MSCP disk devices will have device affinity set to primary processor only and thus reduce IO scalability. They

also do not support asynchronous IO execution on separate IO threads. Instead host IO operations for non-MSCP

storage devices will be executed in the context of VCPU thread, possibly causing a spinlock or mutex held by VCPU

for a long time while blocking host IO operation is in progress and bringing other VCPUs to a stall, should they need

the resource protected by this spinlock or mutex. We recommend therefore limiting the use of non-MSCP disk

devices only for minor, light IO loads, and if possible better avoiding them altogether.