Nepal:Redundancy

This page is meant to layout redundancy plans for Nepal's spring pilot of OLPC. See the Nepal page for more details on the pilot.

The Basic Heuristics for Redundancy

(a) Determine the minimum setup and identify all components that can fail individually. (b) For each failure, what would be the impact to the entire system. (c) Determine an N+1 or N+2 configuration that might address the concern.

Individual XO's

• LiveCD+USB w/ correct image and settings
• ?Possible to restore over the network?
• Need way to XS_backup_restore backup and restore individual student files
• Need extra XO's for teachers, at least N + 1 where N is the # of teachers
• How many extra XO's for kids?

Active Antennas

• Need 3 antennas
• 1 active antenna per 100 students
• 2 antennas in use

?How many clients can an active antenna support?

School Server

There should be two School Servers, one for the 2nd grade class, and one for the 6th grade class. They should mirror each other.

• Disk Failure
  • LiveCD + USB stick
  • Possibly use Fedora's LVM for disk mirroring
• CPU failure
  • Have spare cpu fan on hand
  • Have spare School Server on hand
• System Backups?

Library Server

• Need backup Library server that mirrors the production Library Server

NOTE: The Library Server will be in a centralized location

Internet Connection

Need some kind of commitment from local ISP for both support and service levels

Monitoring

• Nagios for remote monitoring of Internet connection?
• Another tool to report system usage for the school server? ZENOSS?

Tony Pearson has contributed extensively to this plan.