If you wonder what happened: same shit different day.
The current host was brought up hastefully after I got involuntarily committed to a drug rehab and could no longer maintain the hardware. It came with a RAID 0 array of 4 disks, one of which keeps failing (electrical issues) and taking the entire root volume down. Now we cannot easily convert that to RAID 5 since it would force us to go downtime again, dump all data somewhere, reinstall the OS and software from scratch, and move data back in. Though one day we will find enough spare time to resolve these problems.
As always, sorry for inconvenience.