Psychology 2.0

This page has some background information on making backups and explains some basic *nix backup and restore procedures.

Introduction

Your wiki installation contains some unique data in the following directories:

    local/         Local configuration scripts
    cookbook/      Recipes obtained from the Cookbook
    pub/           Publicly accessible files
    wiki.d/        Wiki pages
    uploads/       Uploaded files (attachments)

A good backup plan will include periodically archiving these directories — or at bare minimum local/ and wiki.d/. Good practice dictates keeping your backup archives on a separate machine.

Simple Backup and Restore (*nix)

When it comes to backup, simpler is better. Since the pmwiki distribution is very small (about 1/4 megabyte), it's simplest to just archive the distribution files along with the data.

Making a Backup Archive

The following *nix command, executed from the parent directory of your wiki's directory, will put a complete backup archive of your site in your home directory.

tar -zcvf  ~/wiki-backup-`date +%Y%m`.tar.gz  wiki/

Restoring the Backup Archive

Simple Method

Your site can be restored and running in under 30 seconds with

tar -zxvf ~/wiki-backup-200512.tar.gz
find wiki/uploads/ -type d |xargs chmod 777
find wiki/wiki.d/ -type d |xargs chmod 777

A Slightly-More-Secure Method

The simple restore commands above will give you world-writable files and directories. You can avoid world-writable permissions by letting PmWiki create directories with the proper attributes (ownership and permissions) for you.

Start with

tar -zxvf ~/wiki-backup-200512.tar.gz
rm -rf wiki/wiki.d
rm -rf uploads
chmod 2777 wiki/

Now upload a file in each group that had uploads. If your site doesn't have uploads, just visit your site once so the wiki.d/ directory will be created.

Finish your installation with

chmod 755 wiki/
tar -zxvf ~/wiki-backup-200512.tar.gz

Details

The commands on this page assume your site is in a directory called "wiki/". The test backup was made in December, 2005 so it's named accordingly.

Your site will only have an uploads/ directory if uploads are enabled.

The backup command uses a date stamp (YYYYMM) in the filename. If you automate the command via cron you'll wind up with monthly snapshots of your site. You can get a daily snapshot by appending %d to the date command (`date +%Y%m%d` will get you YYYYMMDD). Be wary of space limitations if you have a large uploads/ directory.