During the afternoon of Sunday 1st July we'll be undertaking some scheduled maintenance in the University's Struben data centre. We will endeavour to schedule this work in such a way that the downtime experienced by individual services is minimised. In particular, we'll try and insure that access to the SEALS library server and the Internet is disrupted for no more than a few minutes. Users should, however, plan their activities on the assumption that the services provided by the machines listed below (including Internet access) will be unavailable from 14:00 until around 20:00 on Sunday.

There are three separate activities that need to be completed:
  1. Upgrade the Struben Core Switch
    This will be a repeat of the upgrade done to the core switch in the Africa Media Matrix a few weeks ago. The upgrade involves several brief (approximately two minutes) network outages over the course of an hour or so. All networking on campus, including access to the Internet and the SEALS library server will be affected by this.

  2. Rewire the Power Distribution Unit in the Services Rack
    The electrical load in one of our racks is exceeding the specifications of the cabling and so we need to perform some preventative maintenance to reduce this load. This involves replacing a length of cabling which, unfortunately, means we'll need to shut down those machines whose power is supplied by this cable. This includes:
    • one of our Internet firewalls
    • three services cluster machines (serving outgoing mail, webmail, proxy, DHCP, DNS, LDAP and RADIUS)
    • eprints.ru.ac.za (Rhodes eResearch Repository)
    • owl.ru.ac.za (hosting moodle.ru.ac.za and ea.ru.ac.za)
    • baboon.ru.ac.za (incoming faxes for switchboard and the Registrar's division)
    • meerkat.ru.ac.za (access control)
    • leopard.ru.ac.za (WINS, anti-virus updates, WSUS)
    • stream.net.ru.ac.za (Windows media streams)

    The first two items on this list have redundant backups available on alternative power supplies and thus the services they provide should still be available to most users on campus. In particular, Internet access should not be affected by this change (although it will be affected by the upgrade mentioned above). Users may notice a brief interruption in service when these servers are initially taken offline whilst their computer changes over to use the alternative servers. Those users with statically configured IP settings may find their DNS servers unavailable.

  3. Relocate Some Servers
    Four machines need to be relocated from an old, now decommissioned rack to a newer rack elsewhere in the data centre. The services offered by these machines will be unavailable for as long as it takes to physically move and recable them. This should take no more than a couple of hours. The machines affected are:
    • elephant.ru.ac.za (incoming mail server, IMAP and mailing lists)
    • iguana.ru.ac.za (web server serving www2.ru.ac.za, campus.ru.ac.za, forums.ru.ac.za, noticeboard.ru.ac.za, people.ru.ac.za, www.ginx.org.za, www.aulai.org.za, ilam.ru.ac.za, ross.ru.ac.za, music.ru.ac.za, and a few other web pages)
    • camel.ru.ac.za (iFolder backup server for staff)
    • pangolin.ru.ac.za (eDirectory replica, authentication)

    No e-mail should be lost whilst elephant is unavailable -- all incoming e-mail should be queued on the remote server. It will, however, take some time for elephant to process all the queued mail once it comes back online.

Some of these changes will be performed in parallel, meaning that you can expect a number of outages to occur simultaneously. Some services may be available intermittently during the process of making these changes.