Clone a ZFS vdev

vdev-clone.sh

#!/bin/bash

set -e

dd_args=(
    "-d"
    "-b" "1M"
    "-B" "4k"
    "-w"
    "-A"
)

warn() {
    echo "$@" >&2
}

die() {
    warn "$@"
    exit 1
}

usage() {
    warn "$( basename "$0" ) device [device [...]]"
}

get_first() {
    key="$1"
    text="$2"

    value=$( echo "$text" | awk "(\$1 == \"$key:\") { print \$2; exit 0; }" )

    echo "${value//\'/}"
}

get_pool() {
    get_first "name" "$@"
}

get_guid() {
    get_first "guid" "$@"
}

get_timestamp() {
    text="$1"

    timestamps=( $( echo "$text" | awk '($1 == "timestamp") { print $3 }' | sort -n ) )

    echo "${timestamps[-1]}"
}

get_output_filename() {
    base="$1"

    n=1
    while [ -f "${base}-${n}.img" ] ; do
        warn "${base}-${n}.img exists." 
        (( n++ ))
    done

    echo "${base}-${n}.img"
}

if [ "$#" -lt 1 ] ; then
    usage
    exit 1
fi

cd /volumes/recovery/disks

for device in "$@" ; do
    if [ ! -e "${device}1" ] ; then
        die "Can't find first partition for device $device"
    fi

    zdb=$( zdb -l -u "${device}1" )

    pool=$( get_pool "$zdb" )
    guid=$( get_guid "$zdb" )
    timestamp=$( get_timestamp "$zdb" )

    echo "Recovering $guid from pool $pool last updated $( date --date="@$timestamp" )..."

    mkdir -pv "${pool}/${guid}"

    filename=$( get_output_filename "${pool}/${guid}/${timestamp}" )
    logfile="${filename%.img}.log"
    badfile="${filename%.img}.bad"

    echo "Cloning $device to $filename (logging to $logfile)..."

    dd_rescue "${dd_args[@]}" -l "$logfile" -o "$badfile" "$device" "$filename"
done