We will be investigating the cause of an audible alarm on Web42 tomorrow (Feb 25th) at 9am GMT.
Depending on the severity we might have to take the server down and if so it will be down between a few minutes and a few hours. We will update this ticket as soon as we have more information tomorrow.
Update: the problem was a degraded RAID. We replaced one of the drives and the server is now back online and the RAID is rebuilding.