INSTALL/ExtendPersistentImg.sh

   1 #!/bin/bash
   2
   3 print_usage() {
   4     echo 'Usage:  ExtendPersistentImg.sh file size'
   5     echo '   file   persistent dat file'
   6     echo '   size   extend size in MB'
   7     echo 'Examples:'
   8     echo '   sh ExtendPersistentImg.sh ubuntu.dat 2048 - This command would extend ubuntu.dat by 2048MB (2GB)'
   9     echo '   sh ExtendPersistentImg.sh ubuntu.dat -2048 - This command reduces ubuntu.dat by 2048MB (-2GB)'
  10     echo ''
  11 }
  12
  13 if [ -z "$1" -o "$1" = "-h" ]; then
  14     print_usage
  15     exit 1
  16 fi
  17
  18 if [ -z "$2" ]; then
  19     print_usage
  20     exit 1
  21 fi
  22
  23 uid=$(id -u)
  24 if [ $uid -ne 0 ]; then
  25     print_err "Please use sudo or run the script as root."
  26     exit 1
  27 fi
  28
  29 if [ "$1" = "__vbash__" ]; then
  30     shift
  31 else
  32     if readlink /bin/sh | grep -q bash; then
  33         :
  34     else
  35         exec /bin/bash $0 "__vbash__" "$@"
  36     fi
  37 fi
  38
  39
  40 file=$1
  41 size=$2
  42
  43 if [ ! -f "$file" ]; then
  44     echo "$file not exist."
  45     exit 1
  46 fi
  47
  48 if echo $size | grep -q "^-"; then
  49     mode="Shrink"
  50     size=${size:1}
  51 else
  52     mode="Extend"
  53 fi
  54
  55 if echo $size | grep -q "[^0-9]"; then
  56     print_usage
  57     exit 1
  58 fi
  59
  60 fsize=$(stat -c '%s' $file)
  61
  62 fsmod=$(expr $fsize % 1024)
  63 if [ $fsmod -ne 0 ]; then
  64     echo "File size of $file is not aligned by 1MB, please check."
  65     exit 1
  66 fi
  67
  68
  69 fsMB=$(expr $fsize / 1024 / 1024)
  70
  71 if [ "$mode" = "Extend" ]; then
  72     total=$(expr $fsMB + $size)
  73 else
  74     if [ $fsMB -le $size ]; then
  75         echo "File size of $file is less than ${size}MB."
  76         exit 1
  77     fi
  78     total=$(expr $fsMB - $size)
  79 fi
  80
  81
  82 magic=$(hexdump -n3 -e  '3/1 "%02X"' $file)
  83 if [ "$magic" = "584653" ]; then
  84     if [ "$mode" = "Shrink" ]; then
  85         echo "Shrink is not supported for XFS filesystem."
  86         exit 1
  87     fi
  88
  89     if which xfs_growfs >/dev/null 2>&1; then
  90         cmd=xfs_growfs
  91     else
  92         echo 'xfs_growfs not found, please install xfsprogs first'
  93         exit 1
  94     fi
  95 else
  96     if which resize2fs >/dev/null 2>&1; then
  97         cmd=resize2fs
  98     else
  99         echo 'resize2fs not found, please install e2fsprogs first'
 100         exit 1
 101     fi
 102 fi
 103
 104 if [ "$mode" = "Extend" ]; then
 105     echo "$mode dat file... (current is ${fsMB}MB, append ${size}MB, total ${total}MB)"
 106     dd if=/dev/zero bs=1M count=$size status=none >> "$file"
 107     sync
 108 else
 109     echo "$mode dat file... (current is ${fsMB}MB, reduce ${size}MB, finally ${total}MB)"
 110 fi
 111
 112
 113 freeloop=$(losetup -f)
 114 losetup $freeloop "$file"
 115
 116 if [ "$cmd" = "resize2fs" ]; then
 117     echo "$mode ext filesystem by resize2fs ..."
 118     echo "resize2fs $freeloop ${total}M"
 119     e2fsck -f $freeloop
 120     resize2fs $freeloop ${total}M
 121     ret=$?
 122 else
 123     echo "$mode xfs filesystem by xfs_growfs ..."
 124     tmpdir=$(mktemp -d)
 125     mount $freeloop $tmpdir
 126     xfs_growfs $freeloop
 127     ret=$?
 128     umount $tmpdir && rm -rf $tmpdir
 129 fi
 130
 131 losetup -d $freeloop
 132
 133 if [ $ret -eq 0 -a "$mode" = "Shrink" ]; then
 134     echo "truncate persistent file ..."
 135     truncate "$file" -s ${total}M
 136     ret=$?
 137 fi
 138
 139 echo ""
 140 if [ $ret -eq 0 ]; then
 141     echo "======= SUCCESS ========="
 142 else
 143     echo "======= FAILED ========="
 144 fi
 145 echo ""