# Pastebin kgzSW2XE
#!/usr/bin/env bash

# Resumes an interrupted zfs receive, displaying an accurate ETA

set -euo pipefail

src=foo/bar@snap
dest=baz/bar
host=baz
rate=1500K
key=/path/to/key
buffersize=10G

ssh-add "$key"
trap "ssh-add -D" EXIT

token=$(ssh "$host" zfs get -H -o value receive_resume_token "$dest")
printf "token:\t$token\n"

read _full _name size < <(zfs send -t "$token" -nP | grep full)
printf "size:\t$size\n"

sudo zfs send -t "$token" | pv -L "$rate" -s "$size" \
    | ssh "$host" "mbuffer -q -m $buffersize | zfs receive -s $dest"