概述

云平台客户的服务器可能会随着业务量的不断增长造成磁盘空间不足的情况，比如：共享文件服务器硬盘空间不足，在这个时候就需要增加磁盘空间，来满足线上的业务；又或者我们在使用linux的过程中, 有时会因为安装系统时分区不当导致有的分区空间不足，而有的分区空间过剩的情况，都可以是使用fdisk分区工具来动态调整分区的大小；

步骤

1.备份

就算是无损的扩容，但难免会出什么意外，备份是必不可少的，一般云平台都有备份功能，可直接对磁盘做一次全量备份。

2.用fdisk重新分区

默认的分区如下

root@i-abnawjwo:/# df

Filesystem 1K-blocks Used Available Use% Mounted on

udev 497752 4 497748 1% /dev

tmpfs 101700 440 101260 1% /run

/dev/sda1 20509308 1337636 18106816 7% /

none 4 0 4 0% /sys/fs/cgroup

none 5120 0 5120 0% /run/lock

none 508488 0 508488 0% /run/shm

none 102400 0 102400 0% /run/user

/dev/sdc1 10190136 23032 9626432 1% /data

root@i-abnawjwo:/data# cat hello

test1

卸载当前的分区umount /dev/sdc1

若是卸载不掉，有可能是有进程再用，可以用fuser或者lsof查看

fuser -m -v /data

fuser -m -v -i -k /data

lsof /data

卸载掉后fdisk删除原来的分区，重新分区， 注意开始的磁柱号要和原来的一致(这是保证数据不丢失的关键步骤)

root@i-abnawjwo:/# umount /data

root@i-abnawjwo:/# fdisk /dev/sdc

Command (m for help): d

Selected partition 1

Command (m for help): n

Partition type:

p primary (0 primary, 0 extended, 4 free)

e extended

Select (default p):

Using default response p

Partition number (1-4, default 1):

Using default value 1

First sector (2048-104857599, default 2048):

Using default value 2048

Last sector, +sectors or +size{K,M,G} (2048-104857599, default 104857599):

Using default value 104857599

Command (m for help): p

Disk /dev/sdc: 53.7 GB, 53687091200 bytes

64 heads, 32 sectors/track, 51200 cylinders, total 104857600 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x305cddae

Device Boot Start End Blocks Id System

/dev/sdc1 2048 104857599 52427776 83 Linux

Command (m for help): wq

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

重启系统

3.检测分区，扩展分区大小

root@i-abnawjwo:~# e2fsck -f /dev/sdb1

e2fsck 1.42.9 (4-Feb-2014)

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

/dev/sdb1: 12/655360 files (0.0% non-contiguous), 79664/2621440 blocks

root@i-abnawjwo:~# resize2fs -p /dev/sdb1

resize2fs 1.42.9 (4-Feb-2014)

Resizing the filesystem on /dev/sdb1 to 13106944 (4k) blocks.

The filesystem on /dev/sdb1 is now 13106944 blocks long.

4.重新挂载，查看分区大小，检查数据

root@i-abnawjwo:~# mount /dev/sdb1 /data/

root@i-abnawjwo:/data# cat hello

acasdcacsa

root@i-abnawjwo:/data# df

Filesystem 1K-blocks Used Available Use% Mounted on

udev 497752 4 497748 1% /dev

tmpfs 101700 428 101272 1% /run

/dev/sda1 20509308 1337768 18106684 7% /

none 4 0 4 0% /sys/fs/cgroup

none 5120 0 5120 0% /run/lock

none 508488 0 508488 0% /run/shm

none 102400 0 102400 0% /run/user

/dev/sdb1 51474044 33100 48803172 1% /data

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。