Home user backup stratergy help

[winnielinnie]

although the dangers dont appear in your testing, is that the main reason why it is not used? I guess the dangers are there in theory

Probably, and much of the sync/backup software was designed with traditional filesystems in mind. They apply their own "copy-on-write" by using "temp" files to mitigate against corruption or partially transferred/interrupted copy operations. The problem is, an application using its own makeshift "copy-on-write" on top of a true copy-on-write filesystem (ZFS, Btrfs) is very inefficient, especially for larger files.

As @HoneyBadger explained in an earlier thread:

Unfortunately it's a consequence of copy-on-write on top of copy-on-write when snapshots come into play - not really an easy way to avoid this.

The only way I found to avoid this is using rsync with "--inplace". No other software I'm familair of does this. If anyone knows of such options, I'd love to hear them.

In fact, rsync doesn't use "--inplace" by default. You must intentionally invoke it.

Otherwise, you'll just have to enjoy the user-friendly GUI of other offerings and just accept that you'll have less efficient snapshots / space consumption on your TrueNAS system. Realistically, the only concern are large files that have been modified between snapshots. (Hence I use Thunderbird, Outlook, and zipped archives as common examples.)