noticeboard.ru.ac.za

2011/10/04 - Core Services Maintenance
On Tuesday 4 October we'll be undertaking major maintenance work on the University's central servers from 5.30PM onwards.

It is expected that all services will continue to be available whilst this scheduled maintenance is underway; the maintenance work is not expected to be service affecting. However, all centrally provided IT services (e-mail, home directories, iprint, web, admin & finance systems, fax, access control, proxy, authentication, etc) will be at risk of an outage. In addition, network services that depend on authentication (wireless networking, VPN access, registration, etc) will also be at risk of an outage. As such, you should not plan any activities during the maintenance period that are critically dependent on these services being available.

This maintenance work is being undertaken in the scheduled maintenance window that was approved by the ITSC last year. It is expected that all work will be completed well before the end of the approved maintenance period (7.30AM on Wednesday morning), and probably before midnight.
During the maintenance period we'll be reconfiguring the cabling that connects many of the University's servers to the network. All the services affected are virtualised, and can be moved between physical servers without interrupting service. Our intention is to work on one physical server at a time, and migrate all running services off that server before starting work. In theory this means that there'll be no service outage; it remains to be seen if this is the case in practice.

In some instances, we need to physically move a host server from one place to another to correct privilege separation problems that arose from their initial installation. Again there should be no running services on the server at the time we do this, and thus no service outage.

One side effect of doing this is that we'll reduce the resource pool available to our central services (there'll be fewer servers, less processor & memory capacity, etc). This might mean that some services run slower than normal or are otherwise degraded, without there being an actual outage.
During the preparation for this scheduled work, we uncovered some network issues that need to be corrected. As a result, some subsidiary network maintenance work will also be taking place during the maintenance window. This work will affect network connectivity in the following buildings:
  • Botany
  • English
  • Geography
  • Geology
  • GLT/ADC/IWR
  • Library
  • Psychology

This work will commence at 5.30PM and should be completed by 9PM. Each building will be affected for between half an hour to an hour.
QUOTE(guy @ Sep 20 2011, 11:43 AM)
In some instances, we need to physically move a host server from one place to another to correct privilege separation problems that arose from their initial installation. Again there should be no running services on the server at the time we do this, and thus no service outage.

We've discovered that we also need to physically move one of our storage systems. If time allows, we intend to move this storage system during the current maintenance window; if not, we'll defer this work until the November maintenance window.

Moving this storage system will affect two servers: serval & zenworks. Unfortunately the latter also affects all public computer laboratory logins. Thus if we do move it, you can expect to be unable to log into public computer lab machines until such time as it is restored (people who are already logged in should be unaffected). It should take roughly an hour to complete this move.

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