This incident has been resolved.
Sep 14, 07:36 CEST
The downgrade was successfully finished yesterday evening. No more servers had been crashed/rebooted. The overall situation is stable now.
Sep 13, 14:43 CEST
We are in the process of downgrading most VM servers now. We will leave some upgraded for further investigation, but will only run selected VMs there.
Sep 12, 15:00 CEST
We will be rolling back a kernel update which was rolled out with release 2019_020.
Meanwhile now other VM server has been rebooted.
Sep 11, 17:29 CEST
We are experiencing occasional (about once a day) VM server reboots. VMs running on a rebooting server are rebooting too, so application availability might be affected.
Sep 11, 11:57 CEST