Why does UPPMAX have a 7 days limit for job length?

UPPMAX announces unplanned service-stop at least 7 days in advance, and the maximum job time of 7 days is applied in order to ensure that all started jobs will have the possibility to complete in time. External parties might require to shut down power or cooling, and UPPMAX has been able to negotiated a 7 days policy for such maintenance actions. An additional reason is that long-running jobs increase the chances of failure, and that the computed time then is wasted (both for the researcher in charge but also for all other UPPMAX users). Other SNIC centra also apply similar rules.