I was wondering how often does one choose to make and keep back ups. I know that “It depends on your business needs”, but that is rather vague and unsatisfying, so I was hoping to hear some heuristics from the community. Like say I had a workstation/desktop that is acting as a server at a shop (taking inventory / sales receipts) and would be using something like timeshift to keep snapshots. I feel like keeping two daily and a weekly would be alright for a store, since the two most recent would not be too old or something. I also feel like using the hourly snapshots would be too taxing on a CPU and might be using to much disk space.
As others have said, with an incremental filesystem level mechanism, the backup process won’t be too taxing for the CPU. I have ZFS set up which makes this easy and I make hourly snapshots using sanoid which also get sent to another mirrored pair of connected drives using syncoid. Then, once a day, I upload encrypted daily snapshots to a bucket in the cloud using restic. Sounds complicated, but actually sanoid/syncoid and restic do all the heavy lifting. All I did is automate their schedules using systemd timers and some scripts to backup the right directories.
How do you upload a snapshot? I’m using TrueNAS where I can make snapshots visible in a otherwise hidden .zfs directory. Do you just backup from there or something similar? Is there an upside to backing up a snapshot instead of just the current data?
Basically, as you said. Mount the data somewhere and back up its contents.
I back up snapshots rather than current data, because I don’t want to stop the running containers that read and write from that data. I’d rather avoid the situation where the container is writing data while it’s being backed up. The back up happens shortly after the daily snapshot is made so the difference between current and snapshot data is small.