I asked our server farm tech team to babysit the routine self-upgrade of the system software, something that happens once a month +/- without difficulty. When the system came up from upgrade, the VM could not see any network devices. After they escalated internally, still no luck. So, they had to do a backup/copy (via iSCSI attached disks since no network connection) and restore to a new VM.Although it did not effect this site, a chance from PHP 5.x to 7.x broke the main site on this server and shut down all order taking/product configuration procedures at my friend's factory, so I had to worry about giving him a stroke while straightening this mess out, with an absence while I attended to the day job at the company that likely made the computer you are using now.But, we did not lose a single posting during the process. The only user visible impact was about 10 hours of downtime.