Today I used the SL downtime to move the server to a new case. The problem with the old one was that it had a non-standard layout, a weird power supply with fans that were failing and cooled hard disks poorly. It also got full of dust quickly due to the layout and lack of an air filter. All those problems have been fixed by moving the hardware to a rack case.
With this change, the server should run very well as it is for a long time, barring disk failure or something else of the sort, and the improved hard disk cooling should make that unlikely.