Rhodes' central IMAP server will be taken down for a critical hardware upgrade at 15:00 today. It is anticipated that this upgrade will take two to three hours to complete. Work will continue until the service is restored in order to ensure that normal mail facilities become available during the course of this evening.
During this time users will not be able to read e-mail stored on the central IMAP server. Outgoing mail sent to mail.ru.ac.za will still be processed, with local deliveries being queued until the server is restored.
For those interested in the technicalities, two things are going to happen to the server during this scheduled downtime. The first is that its processors will be upgraded from two Intel Xeon 2.8GHz processors to two 3.2GHz processors. This is quite a delicate operation that requires several BIOS and baseboard management controller updates to be performed in the right sequence, as well as the complete disassembly and reassembly of the machine and, as such, will take up the bulk of the downtime.
The second is that a faulty disk in the RAID array will be replaced to bring the array back up to its optimal state of fully redundant with one hot spare (there is no spare but a fully populated RAID 5 array at present). This is a comparatively minor operation that will take a few minutes. The disk rebuild will take a few hours to complete once the machine comes back up but this won't afffect the normal operation of the server.