A 3 second long search in these forums with the search term “backup” gave me this amazing thread:
I added a few things for other operation systems better than windoze, yes there are things better than windoze.
Another incredible thing that made it into the client when you are undocked in space are the overview settings which look like a smaller “settings” icon of what you see here on this very website on the top left, left of your character picture.
Go to “misc” and export the settings to a file named “YourOverviewBackupFile” which creates a file named “YourOverviewBackupFile.yaml” in /Documents/EVE/overview/ (Linux and mac os).
Whenever you make changes to your overview, export it again and say “yes” to the question if you want to overwrite that file.
Backup that file often and save it in da cloud.
Whenever your overview settings are lost, import that file back and go forth and gank someone - preferably not me.