How do I make a BTRFS incremental backup to multiple source destinations, so I don't have to run btrfs send
multiple times?
btrfs send -p /tmp/parent_subvol /tmp/incremental_backup_snapshot | btrfs receive /mnt/destination_drive1
btrfs send -p /tmp/parent_subvol /tmp/incremental_backup_snapshot | btrfs receive /mnt/destination_drive2