

Devops will have more job openings, network will have a higher salary, especially as you become more senior.
Devops people who don’t know networking and/or general traditional sysadmin work are a crushing pain in the ass for those of us who have to support them though. Networking background will make you better at devops, but not necessarily vice versa.
Why do tape drives seen to be best? What’s your use case? They’re still used in enterprise environments because they’re insanely dense compared to hard disks, and it’s real easy to load a truck with a few petabytes to ship elsewhere. Is that what you need? Density? Seems like not for just a few gigs.
If you want backups you need to ship your media, tapes or otherwise, off-site.
Pop your files into a cloud service and call it done. If you’re looking for long term archives and don’t want to use other people’s computers, burn some DVDs and store them at someone else’s house.