Home
VOV Subsystem Administrator Guide
This manual provides information about managing a VOV project, including starting the server and connecting computing resources such as computers and licenses.
IT Administrator Topics
Network Overhead
VOV lets you distribute computation across the network without adding significant overhead. In some cases, it pays to be careful about the distribution of data and computation.

Welcome
What's New
View new features for VOV Subsystem 2025.1.0.
Overview
Discover the workspace, licensing and installation, and training.
VOV Subsystem Tutorials
Discover VOV Subsystem functionality with interactive tutorials.
VOV Subsystem Administrator Guide
This manual provides information about managing a VOV project, including starting the server and connecting computing resources such as computers and licenses.
- Client/Server Architecture
  All of Altair Accelerator's products are based on a client/server architecture to support concurrent activities, team coordination, distributed data management, and distributed processing. The program vovserver runs in the background as a service to implement the main product features. It is the server.
- VOV Projects
  A "project" is a named collection of jobs, together with all the files that are used and produced by those jobs. The contents of VOV projects can be custom organized.
- VOV Registry
  The VOV Registry contains the list of all projects known to an installation of Altair Accelerator software. The registry is used by the vovproject command, and stores metadata such as the host machine and port number of a project.
- Get Started
- Start and Configure the Server
- Connect to a Project
- Stop the Server
- Recovery and Redundancy
- Files, Equivalences, Exclusions
  The files used in a project reside in one or more directories spread all around your filesystems. Each logical name defined in the equiv.tcl file implicitly declares the root of a workspace. You can browse the workspaces using the browser interface.
- Taskers
  A tasker is a VOV client that provides computing resources, specifically CPU cycles, to the vovserver.
- Tasker Policies
- Interfaces to Accelerator, SGE, LSF, and Others
  FlowTracer can be used also as a front end to an existing batch processing system (BPS), for example, Accelerator, LSF, SGE, SGEEE, etc.
- Advanced Tasker Topics
- Resource Management
  Altair Accelerator includes a subsystem for managing computing resources. This allows the design team to factor in various constraints regarding hardware and software resources, as well as site policy constraints.
- IT Administrator Topics
  - SSH Setup
    If you use SSH to login onto certain machines in your LAN that you want to use as taskers, you need to setup SSH so that it will not ask for your password.
  - Network Conditioning
    Each computer has its own clock. Clocks on different computers in the same network might not be synchronized. The system administrator should keep all clocks in the network synchronized.
  - File System Offsets
    The file system that contains the design files may reside on a machine that is not the same as the one where the vovserver is running. The clocks in the two machines may be different, resulting in an offset. These offsets can be easily avoided. Here we show what can be done to work with an unsynchronized network.
  - NFS and VOV
    Before you can use NFS, be it as server or client, you must make sure your kernel has NFS support compiled in.
  - Network Overhead
    VOV lets you distribute computation across the network without adding significant overhead. In some cases, it pays to be careful about the distribution of data and computation.
  - Using PAM (Pluggable Authentication Modules) for Browser Authentication
  - Attribute Value Stream (AVS) File Syntax
    Attribute Value Stream (AVS) is a file format and data interchange format that uses human-readable text to describe nested objects and arrays of objects. This file format is similar to JSON (Javascript Object Notation).
  - Known Issues
  - Health Monitoring and vovnotifyd
  - Limits for Objects and Strings
  - VovScope
    VovScope is a vovserver performance logging mode. When enabled, logging is activated for certain classes of vovserver activity including system calls and network communication to clients.
VOV Subsystem Reference Guide
EDA Tool Integration Guide
This document is a collection of techniques that have proven to be useful when applying FlowTracer in Electronic Design Automation.

View All Altair Accelerator Help

Network Overhead

VOV lets you distribute computation across the network without adding significant overhead. In some cases, it pays to be careful about the distribution of data and computation.

The following table shows the time it takes to archive the same 6.3MB Linux library using the same Linux CPU (called "reno") and varying the location of the modules and that of the target library.


CPU	Modules	Library	Time
reno	tahoe	tahoe	1m42s
reno	tahoe	reno	47s
reno	reno	reno	5s

In all cases the network is a rather quiet standard 10BaseT Ethernet, the machine "tahoe" is a Sparc5/110 running Solaris2.5 (that is a sun5), and the command to build the library was of the type:

% ar rscv LIBRARYNAME.a *.o

Building the library across the network takes almost 2 minutes, while doing the same operation locally takes just 5 seconds. The difference is explained by extra disk and network traffic. Just copying the object files from the sun5 to the Linux box takes 29 seconds.

For other operations, such as linking of large binary files, the difference may be even more dramatic. The point is that, if you want speed, you must limit the network traffic. With VOV this is easy and can be made completely transparent to the end users.

You allocate disk space on various machines in the network and, as part of your design methodology, you include operations that move the data intelligently between the disks. It is easy to constrain some operations to be performed on the machine that physically owns the data; use the Job Editor and modify the Resources field. For example, if the Linux box with the disk space is called "reno," you can restrict selected tools to run on it by setting the Resources field to reno.