[fps_doug]

Don't do simple rolling backups, use something with deduplication like borg backup or ZFS/btrfs if you want to do it at the FS level. The backup size should not increase by much more than the actual size of any new files, so if suddenly, you need twice as much backup space because all your files seem to have changed, you should get suspicious.

[deeesstoronto]

Also ensure your client does not have access to the backup server share so that ransomware can't encrypt backups on a network drive etc.

My backup solution (backuppc/other syncs + zfs + sanoid/syncoid plus offsite server with zfs) means the backup server pulls files from the clients using backuppc/rsync. The backup server volume is zfs snapshoted regularly using sanoid. The offsite server pulls these from the backup server via syncoid/zfs send.

I'm not using rsync.net since I have my own infrastructure, but would definitely choose it as the offsite server if needed.

[iforgotpassword]

Yes this. I use Borg via ssh to an off-site server. With the proper ssh config (force-command, no pty, no forwarding etc) you can lock it down pretty well, especially since you can add an "append only" switch to the serve command that will refuse any modifications or deletions to existing snapshots.

[temp2022account]

Seconded, I have an external 2tb HDD that stores 1 years worth of daily backups from my 256gb (~180gb used at any time) laptop hard drive. My backup script (https://gist.github.com/Jeffrey-P-McAteer/7d4b9052825914b5e0...) takes maybe 30 minutes for a full backup, 5 minutes for most deltas. Files which are the same get hard-linked to the previous days backups, new files are copied over and content-de-duped by btrfs.

[0cf8612b2e1e]

If nothing else, external hard drives are cheap and robust enough that I think more people should invest in having an offsite backup. Annually make a full backup, write the date on the outside, and leave it at the parents house. Make that your family holiday ritual.

[gattr]

As of recently, my setup for backups consists of 2x4 TB HDDs (from different manufacturers) with BTRFS in RAID 1, plugged into a small 2-drive USB3 docking station. With both checksumming and mirroring, feels pretty safe from HW-failure/bit rot standpoint (if one disk fails, you can still mount the other in "degraded" mode).

[wyager]

Agreed. I'll shill rsync.net (no affiliation, just a happy customer) and their ZFS VM backup service. It's basically just a lightweight freebsd VM with a big ZFS volume attached, so you can `zfs send` incremental backups to it, and they support meta-snapshotting of your backup machine on their end. I wrote https://github.com/wyager/zfs-backup to manage my automatic incremental backups, and there are a number of other tools like this.