Here's a strange one with SME 5.1.2
I was using the server (MySQL, PHP, Samba mounts, Web Proxy etc) when the backup started. After a few minutes the internal network stopped responding. I waited for the backups to finish (assuming the internal network was disabled while the backups were ongoing) - the internal network was still dead.
So I rebooted my Windows machine thinking it had got confused by the dropped network - still dead. I found I could connect to server-manager through the console, so the web servers and databases were still running, it was just the internal network that did not work at all. No ping, no DNS, no web services, no Samba - nothing.
So - could this be a hardware problem, or is there something going on that kills network processes if you do certain things while the backup is running? Has this happened to anyone else, or is this a one off? A warn reboot via server-manager fixed the problem.
Jason