参考阿里云云盘扩容方法：https://help.aliyun.com/document_detail/25452.html
root@eth-public-01:~# fdisk /dev/xvdb
Welcome to fdisk (util-linux 2.27.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): m # 帮助命令
Help:
DOS (MBR)
a toggle a bootable flag
b edit nested BSD disklabel
c toggle the dos compatibility flag
Generic
d delete a partition
F list free unpartitioned space
l list known partition types
n add a new partition
p print the partition table
t change a partition type
v verify the partition table
i print information about a partition
Misc
m print this menu
u change display/entry units
x extra functionality (experts only)
Script
I load disk layout from sfdisk script file
O dump disk layout to sfdisk script file
Save & Exit
w write table to disk and exit
q quit without saving changes
Create a new label
g create a new empty GPT partition table
G create a new empty SGI (IRIX) partition table
o create a new empty DOS partition table
s create a new empty Sun partition table
Command (m for help): d # 删除原分区 不会丢失数据
Selected partition 1
Partition 1 has been deleted.
Command (m for help): n # 创建分区
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p # 主分区
Partition number (1-4, default 1): # 直接回车
First sector (2048-734003199, default 2048): # 直接回车
Last sector, +sectors or +size{K,M,G,T,P} (2048-734003199, default 734003199): # 直接回车
Created a new partition 1 of type 'Linux' and of size 350 GiB.
Command (m for help): wq # 保存退出
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
# ubuntu好像会自动挂载，再手动卸载它。
root@eth-public-01:~# umount /dev/xvdb1
root@eth-public-01:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 7.9G 0 7.9G 0% /dev
tmpfs 1.6G 8.7M 1.6G 1% /run
/dev/xvda1 18G 7.4G 9.2G 45% /
tmpfs 7.9G 0 7.9G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 7.9G 0 7.9G 0% /sys/fs/cgroup
tmpfs 1.6G 0 1.6G 0% /run/user/0
# 检查文件系统
root@eth-public-01:~# e2fsck -f /dev/xvdb1
e2fsck 1.42.13 (17-May-2015)
Pass 1: Checking inodes, blocks, and sizes
resizPass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/xvdb1: 110213/13107200 files (69.6% non-contiguous), 52423642/52428544 blocks
# 变更文件系统大小
root@eth-public-01:~# resize2fs /dev/xvdb1
resize2fs 1.42.13 (17-May-2015)
Resizing the filesystem on /dev/xvdb1 to 91750144 (4k) blocks.
The filesystem on /dev/xvdb1 is now 91750144 (4k) blocks long.
# 重新挂载即可
root@eth-public-01:~# mount -a # 我这里已经写到/etc/fstab了
root@eth-public-01:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 7.9G 0 7.9G 0% /dev
tmpfs 1.6G 8.7M 1.6G 1% /run
/dev/xvda1 18G 7.4G 9.2G 45% /
tmpfs 7.9G 0 7.9G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 7.9G 0 7.9G 0% /sys/fs/cgroup
tmpfs 1.6G 0 1.6G 0% /run/user/0
/dev/xvdb1 345G 197G 131G 61% /home
这样就实现数据不丢失且实现分区扩容。
