Not really sure how to format it yet, but btrfs send/receive opens up quite a few possibilities.
btrfs send is mostly file read, with the caveat that the file wanted is on a btrfs subvolume, the subvolume is readonly and you're ok with getting all other files too. You could filter the files by maybe doing strategic snapshots on either side of the file creation and doing an incremental snapshot to get just that one file.
btrfs receive, allows one to create any files in a new subvolume.
btrfs receive, if there's already a volume (let's say with a rootfs) allows applying an incremental snapshot where the new filesystem has any of the files changed (eg: unprivileged executables can now do suid, or any suid executables have contents changed).
This actually comes into play. Systems like btrbk suggest adding btrfs as a sudoer command for remote hosts sending backups over. If those remote hosts go rogue, you could have some evil files on the local filesystem.
I was gonna say send/receive could be similar to a subset of dd (dding a new filesystem to a block device leads to something similar to what btrfs receive gets you after you mount the filesystem), but then #581.
Not really sure how to format it yet, but btrfs send/receive opens up quite a few possibilities.
btrfs sendis mostlyfile read, with the caveat that the file wanted is on a btrfs subvolume, the subvolume is readonly and you're ok with getting all other files too. You could filter the files by maybe doing strategic snapshots on either side of the file creation and doing an incremental snapshot to get just that one file.btrfs receive, allows one to create any files in a new subvolume.btrfs receive, if there's already a volume (let's say with a rootfs) allows applying an incremental snapshot where the new filesystem has any of the files changed (eg: unprivileged executables can now do suid, or any suid executables have contents changed).This actually comes into play. Systems like btrbk suggest adding
btrfsas a sudoer command for remote hosts sending backups over. If those remote hosts go rogue, you could have some evil files on the local filesystem.I was gonna say send/receive could be similar to a subset of dd (dding a new filesystem to a block device leads to something similar to what btrfs receive gets you after you mount the filesystem), but then #581.