30-zpool-detailed

#!/usr/bin/env bash
# NAME:      30-zpool-detailed
#
# DESCRIPTION: Report the Zpool percent used, capacity and free space. By
#              default it will show 2 levels of datasets. This can be
#              adjusted with the "zfs_list_DS_depth" variable.  Datasets
#              smaller than 1% used are not displayed to reduce clutter.
#              This can be adjust with "skip_ds_smaller_than".
#
# Originally Based on work from Mike Roach (https://github.com/mroach)
#
# AUTHOR     : Richard J. DURSO
# DATE       : 01/13/2025
# VERSION    : 1.3
##############################################################################

#!/usr/bin/env bash

set -euo pipefail

# How many levels of datasets to report on.
zfs_list_DS_depth=2

# Capture ZFS dataset list by requested depth
readarray -t zfs_list_DS < <(zfs list -Hp -t filesystem,volume -o space -d"${zfs_list_DS_depth}")

# Skip datasets at less than 1% usage to reduce clutter.
skip_ds_smaller_than=1

size_format=iec
bar_width=60
warn_free_pct=20
red="\e[1;31m"
green="\e[1;32m"
dim="\e[2m"
reset="\e[0m"
ds_char="▪"
snap_char="◆"
other_char="■"
free_char="□"

function format_bytes() {
  numfmt --to="${size_format}" --format="%.01f" "$1"
}

function pct() {
  awk -v n="$1" -v d="$2" 'BEGIN{ print int(n*100.0/d) }'
}

function bar() {
  ds_b="$1"
  snap_b="$2"
  other_b="$3"

  ds_width=$(( (ds_b * bar_width) / 100))
  snap_width=$(( (snap_b * bar_width) / 100))
  other_width=$(( (other_b * bar_width) / 100 ))
  rem=$(( bar_width - ds_width - snap_width - other_width ))

  pct_free=$(( 100 - ds_width - snap_width - other_width ))

  echo -ne "${dim}[${reset}"

  if [ "$pct_free" -lt "$warn_free_pct" ]; then
    echo -ne "$red"
  else
    echo -ne "$green"
  fi

  if [ $ds_width -gt 0 ]; then
    printf "${ds_char}%.0s" $(seq 1 $ds_width)
  fi

  if [ $snap_width -gt 0 ]; then
    printf "${snap_char}%.0s" $(seq 1 $snap_width)
  fi

  if [ $other_width -gt 0 ]; then
    printf "${other_char}%.0s" $(seq 1 $other_width)
  fi

  if [ $rem -gt 0 ]; then
    printf "${reset}${dim}${free_char}%.0s" $(seq 1 $rem)
    # To pad with spaces, do this instead:
    #printf "${dim}%*s" $rem
  fi

  echo -ne "${reset}${dim}]${reset}"
}

# Filter out datasets with a percent used smaller than "skip_ds_smaller_than" and
# determine the column with needed to show the pool and datasets based on depth
# of datasets to show while not considering datasets filtered out.

function remove_unused_DS() {
  local index=0
  local length=0
  col_width=0

  for line in "${zfs_list_DS[@]}"; do
    IFS=$'\t' read -r -a props <<< "$line"

    name="${props[0]}"
    avail="${props[1]}"
    used="${props[2]}"
    capacity=$(( used + avail ))
    used_pct=$(pct "$used" "$capacity")

    if [ "$used_pct" -lt "$skip_ds_smaller_than" ]; then
      # Small dataset remove from array
      unset 'zfs_list_DS[index]'
    else
      # Get length of this dataset name
      length="${#name}"
      # See if dataset name is longer then the previous longest name
      (( length > col_width )) && col_width=$length
    fi
    ((++index))
  done
}

# Filter out small datasets and calculate col_width to use in output
remove_unused_DS

# zpool status
printf "\nzpool status:%s\n" "$(zpool status -x | sed -e 's/^/  /')"
echo

for line in "${zfs_list_DS[@]}"; do
  IFS=$'\t' read -r -a props <<< "$line"

  name="${props[0]}"
  avail="${props[1]}"
  used="${props[2]}"
  usedsnap="${props[3]}"
  usedds="${props[4]}"

  used_other=$(( used - usedsnap - usedds ))
  capacity=$(( used + avail ))

  used_pct=$(pct "$used" "$capacity")
  ds_used_pct=$(pct "$usedds" "$capacity")
  snap_used_pct=$(pct "$usedsnap" "$capacity")
  other_used_pct=$(pct "$used_other" "$capacity")

  #echo "$name avail=$avail used=$used usnap=$usedsnap uds=$usedds cap=$capacity dp=$ds_used_pct sp=$snap_used_pct"

  # Maybe remove the pool name
  local_name="${name#*/}"
  if [ "$local_name" = "$name" ]; then
    # pool name line
    pool_length="${#local_name}"
    printf "%-*s" "$((col_width - 2))" "$name"
  else
    # dataset line
    printf "%-*s" "$((col_width - 2))" "  $local_name"
  fi
  bar "$ds_used_pct" "$snap_used_pct" "$other_used_pct"
  #printf "Used %6s of %6s (%6s free)\n" "$(format_bytes "$used")" "$(format_bytes "$capacity")" "$(format_bytes "$avail")"
  printf "%3s%% used of %6s (%6s free)\n" "$used_pct" "$(format_bytes "$capacity")" "$(format_bytes "$avail")"
done

# Print Character Legend
printf "%-*s" "$((col_width - pool_length +1))" ""
echo -ne " ${dim}[${reset}${green}${ds_char}${reset}${dim}]${reset}=Datasets,"
echo -ne " ${dim}[${reset}${green}${snap_char}${reset}${dim}]${reset}=Snapshots,"
echo -ne " ${dim}[${reset}${green}${other_char}${reset}${dim}]${reset}=Other,"
echo -e  " ${dim}[${reset}${free_char}${reset}${dim}]${reset}=Free Space"