最後更新: 2020-07-26

介紹

resize2fs - ext2/ext3/ext4 file system resizer

目錄

• Expand with parted
• resize2fs
• 減容量(LVM)

Expand with parted

Step

1. parted
2. resize2fs

parted: Resize partition first

(parted) select /dev/md0

(parted) resize 1 0 20G

如果 parted 不支援 resize, 那就要 rm 後再 mkpart

過程

parted /dev/sda

(parted) print

Number Start  End Size Type    File system Flags
1      S      E   M    primary T

(parted) rm 1
(parted) mkpart primary T S NewSize
(parted) quit

resize2fs: resize filesystem

 * ext3, ext4 support online resize (du 時會見到它(fs)會不斷變大)

 * 正確要 enlarge or shrink an unmounted file system

在 resize 前, 它會建議

resize2fs 1.42 (29-Nov-2011)
Please run 'e2fsck -f /dev/lxc/vps1' first.

行一次 fsck:

e2fsck -f /dev/sda3

e2fsck 1.41.14 (22-Dec-2010)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/: 869865/9797632 files (0.6% non-contiguous), 3491321/19565161 blocks

Example

當沒有指定 device 的 size, 那 resize2fs 會把 partition 擴到最大

resize2fs /dev/sda3 2500M

resize2fs /dev/sda3 25G

單位:

• 'M'
•  'G'

Useful opts:

• -p     Prints out a percentage completion bars
• -P     Print the minimum size of the filesystem

Estimated minimum size of the filesystem: 15916657

• -M    Shrink the filesystem to the minimum size.

減容量(LVM)

Step

1. Shrinking the filesystem
2. Shrinking the block device(Partition)

umount /dev/mapper/vg3t-backup

# resize2fs 必須要你 e2fsck

e2fsck -f /dev/mapper/vg3t-backup

# Shrinking to size 300G

resize2fs /dev/mapper/vg3t-backup 300G

# count X size = 300G

dumpe2fs -h /dev/mapper/vg3t-backup

Block count:              78643200
Block size:               4096

lvreduce -L300G /dev/mapper/vg3t-backup

  WARNING: Reducing active logical volume to 300.00 GiB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)

Do you really want to reduce backup? [y/n]: y

lvdisplay vg3t/backup