The site has been down for about a day. The hoster, when asked, said
The home partition usage became exceeded so that we had to add a new drive to fix it. Currently we are working on the server and all the issues will be fixed soon.
Seems like they are real amateurs. The hosting is linux based. And it seems that they do not have proper monitoring and safeguards in place to provide reliable hosting. I may move to another hoster sooner than I had planned.
At this point I still can’t get in to maintain the site or backup the databases and FTP does not work.