WikiBackups

Current

• Every revision of every page is kept in the "Revisions" system.
• The entire system, including pictures, is backed up offsite once a day.

More AboutThisSystem

History

October 2001

DanielMacKay says: I wrote a backup system that saves any page that changes, plus the deltas, six times a day. The backup system it keeps a copy of the entire site in a different place geographically in case of disasters, e.g. sysstem manager error, software bug, disk failure, catastrophic server failure, or any other prolonged system unavailability.

The page is in two parts:

1. "Deltas" shows just the changes to recently-changed pages in a format similar to RecentChanges; however, it shows exactly what's changed. If something's been added to the page, that piece of text is marked with Add .. if deleted, Rem. Typically a change to a paragraph will show as a Rem and an Add. Scroll sideways to find the change -- you can see that even a single punctuation change to a page is easy to see.
2. "Versions" contains the complete text of pages which have changed in the last month and the previous version. The notation "040412.2015, 511" means the version of the file that existed at 8:15pm on 12th of April, 2004 was 511 bytes. This part of the report is used to restore pages that have been completely destroyed. With two clicks you can restore any page. Every version of every page is kept forever, but only the last months' worth are shown.

When you view either part, at the bottom is a link to "Edit" or "View" the page to make repairing damage and accidental changes even easier.

This set of backups is itself is backed up to a third geographically different site once a day.

It doesn't back up RecentChanges and can be configured to skip other pages if necessary.

Nov 2001

Small mods to

• cope with a database problem, and
• to keep previous versions of pages that haven't been modified for a long time, on the display page for a week after they *do* get modified.
• Writes tempfiles to /tmp for MUCH faster operation; backs up in << 30 seconds instead of ~1min.
• Also, the backup display program only shows recently modified pages.

Jan 2004

Following some heavy promotional work, I've set the backup system to run once an hour - we can expect lots of changes.

Other stuff about backups:

• is http://www.computerworld.com/securitytopics/security/recovery/story/0,10801,64128,00.html a story about how backups did and didn't work during the WTC disaster.
• is http://www.taobackup.com/ the Tao of Backup

February 2006

The new wiki server software, "oddmuse" includes version control, so we have discontinued the auxiliary backup system. The entire wiki is still backed up off site once a day.