expand_lv.sh

#!/bin/bash
# This script will check if there is unallocated space in the volume group
# and will attempt to expand logical volume and file system using resize2fs
# Author: Stas Alekseev <[email protected]>

fs_mount="/var"
vg_minfree_mb="100000"
lv_maxsize_mb="27000"

warn () {
  echo "$0:" "$@" >&2
}

die () {
  rc=$1
  shift
  warn "$@"
  exit $rc
}

show_help() {
cat << EOF
Usage: ${0##*/} [-h] [-f filesystem_mountpoint] [-v vg_minsize] [-l lv_maxsize]
This script will check if there is unallocated space in the volume group
and will attempt to expand logical volume and file system using resize2fs.

  -h                        display this help and exit
  -f filesystem_mountpoint  expand this filesystem (default: ${fs_mount})
  -v vg_minsize             minimum number of megabytes availabe in volume group (default: ${vg_minfree_mb})
  -l lv_maxsize             expand only if logical volume is less then ${lv_maxsize_mb} (default) megabytes
EOF
}

while getopts "hf:v:l:" opt; do
  case "$opt" in
    h)
        show_help
        exit 0
        ;;
    f)  fs_mount=$OPTARG
        ;;
    v)  vg_minfree_mb=$OPTARG
        ;;
    l)  lv_maxsize_mb=$OPTARG
        ;;
    '?')
        show_help >&2
        exit 1
        ;;
  esac
done

if [[ $UID != 0 ]]; then
	echo "Root access not obtained! Exiting."
	exit 1
fi

fs_actual_mount=$( cat /proc/mounts | awk '{print $2,$1,$3}' | grep -E "^$fs_mount " ) ||
  die 1 "$fs_mount mount not found, check if it's mounted."
fs_device=$( echo "$fs_actual_mount" |  awk '{print $2}' )
lvs=$( lvs -o vg_name,vg_size,vg_free,lv_name,lv_size,lv_dm_path --units m --separator "|" --noheadings --nosuffix | grep "$fs_device" ) ||
  die 1 "Logical volume for $fs_mount not found."
vg_free=$( echo "$lvs" | awk 'BEGIN { FS = "|" } ; { print $3 }' | cut -d. -f1 )
lv_size=$( echo "$lvs" | awk 'BEGIN { FS = "|" } ; { print $5 }' | cut -d. -f1 )

if [ "$vg_free" -lt "$vg_minfree_mb" ]
then
  die 1 "Not enough space in Volume Group"
fi

if [ "$lv_size" -gt "$lv_maxsize_mb" ]
then
  die 0 "Logical Volume for $fs_mount is already $lv_size MB which is bigger then $lv_maxsize_mb MB maximum size for this script."
fi

fs_type=$(echo $fs_actual_mount | awk '{print $3}')
if [[ "$fs_type" != "ext4" && "$fs_type" != "ext3" ]]
then
  die 1 "I do not know how to exand this filesystem: $fs_type"
fi

lvextend -r -L ${lv_maxsize_mb}M $fs_device || die 1 "Failed to extend Logical Volume for $fs_mount"