For this week's #hamchallenge : My primary logging software is #Wavelog. The webserver and backend database both run on virtualized machines in a #HighAvailability #Proxmox #cluster (same one that hosts this instance!). Those are backed up daily to another machine on site via PBS, then those backups are synced to a remote server running in a house in another city.
In addition, my log is also synced to both #QRZ and #LOTW every 6 hours or so, but I didn't think it qualifies as a true backup, since there is some data which those logs don't record.