Command Syntax: arcvreset

Copyright 2008 by Stephen Vermeulen
Last updated: 2008 Oct 12


Introduction

This is part of a series of articles on backing up computers. The top page is Design for an Archiving Backup System.

This page describes the command line syntax of the arcvreset.py program.

Purpose

The arcvreset.py program is a utility to inspect and reset the next package ID and next backup event IDs in the ZODB.

The arcvback.py and service.py programs keep this information in the top level of the version database directory. The two pieces of information are:
  1. the next package ID to be used (nextPID)
  2. the next backup event ID to be used (nextEID)
In the event that you have erased an old backup database and are preparing for a new backup cycle you may wish to set the nextPID and nextEID values so that they carry on after the old backup set. You might also want to have several independent backups running concurrently, and in this case you might want to preset the initial BID and EID values for each backup set so that they don't overlap (in case you get the packages intermixed). Since the maximum values of PID and BID are in the 4 billion range (well with Python 2.3 this should actually be unlimited but I have not tested it...) there is plenty of room to partition the PID and EID ranges to prevent overlap.

Syntax

The arcvreset.py program gets its configuration information from the config.ini file.

The full command syntax is:

arcvreset [-h] [-ini path/config.ini] [-PID pid] [-EID eid]

where items in the square brackets are optional.

If you run it without any parameters it just prints the current values of the nextPID and nextEID for the version database defined in the default config.ini.

Options

The -h parameter will bring up a short syntax help prompt and then stop.

The -ini parameter allows you to specify an alternate config.ini file.

The -PID parameter specifies a new value to set the next package ID to. It will not let you reduce the current value of PID as that can lead to duplication issues

The -EID parameter specifies a new value to set the next package ID to. It will not let you reduce the current value of EID as that can lead to duplication issues


                back to arcvback.com home