The server will be rebooted on 30 April for a kernel upgrade, and depending on what else is happening I may take the opportunity to upgrade Discourse as well.
Target time is Unixtime 1588230000: about 8am UK (midnight-3am USA, 9-10am Europe, 3-5pm Australia) and this should take less than an hour.
https://status.firedrake.org/ will show you any status updates I post; “leuchtend” is the relevant server.
7 pm New Zealand, just in case 
This work is now complete.
You know, it would be really useful if there were a service to say "give me a world map showing the the time everywhere at this particular moment. But I can’t see one out there. I shall probably have to write it…
Looks as if there’s a fair bit of background image processing being done following this new upgrade (it looks as though it’s converting lots of JPEGs to PNG thumbnails), and the system load is currently quite high. Sorry about that. Worst case, if the forum ends up needing to be migrated to a gruntier machine, that’s a thing I can do.
Looks as if the image conversion has now finished and system load is back to normal.