centos下使用fdisk扩展分区容量大小
硬盘空间为20G，VMware增加磁盘大小，需要再增加10G空间
扩展完后，重启系统，再次使用fdisk -l查看，会发现硬盘空间变大了；
重新创建分区，调整分区信息
本次实验主要对/dev/sda4这个分区扩展，如果是生产环境，请提前做好备份保存到其他分区，虽然扩展分区大小不会导致数据丢失，安全起见，请提前做好备份；
首先模拟出一些数据：
[root@linuxprobe data]# mkdir test [root@linuxprobe data]# echo "we are Linuxer" > linuxprobe [root@linuxprobe data]# ll total 24 -rw-r--r--. 1 root root 15 May 23 21:59 linuxprobe drwx------. 2 root root 16384 May 23 15:07 lost+found drwxr-xr-x. 2 root root 4096 May 23 21:51 test [root@linuxprobe ~]# umount /dev/sda4 #卸载磁盘分区
若提示磁盘忙，使用fuser找出将正在使用磁盘的程序并结束掉；
fuser -m -v /data fuser -m -v -i -k /data
使用fdisk工具先删除/dev/sda4分区，然后创建新分区，注意开始的磁柱号要和原来的一致（是保证数据不丢失的关键步骤），结束的磁柱号默认回车使用全部磁盘。
[root@linuxprobe ~]# fdisk /dev/sda
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): p #查看分区表信息Disk /dev/sda: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005210c
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 1301 10240000 83 Linux
/dev/sda3 1301 1497 1572864 82 Linux swap / Solaris
/dev/sda4 1497 2611 8952832 83 Linux
Command (m for help): d #删除分区Partition number (1-4): 4 #删除第四个Command (m for help): p #再次查看分区信息，/dev/sda4已被删除Disk /dev/sda: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005210c
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 1301 10240000 83 Linux
/dev/sda3 1301 1497 1572864 82 Linux swap / Solaris
Command (m for help): n #创建新的分区Command action
e extended
p primary partition (1-4)
p #创建为主分区
Selected partition 4
First cylinder (1497-3916, default 1497): #经对比，正好和上一个磁盘柱一致，默认即可Using default value 1497
Last cylinder, +cylinders or +size{K,M,G} (1497-3916, default 3916):
Using default value 3916 #直接默认就可以Command (m for help): p #查看分区表信息Disk /dev/sda: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005210c
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 1301 10240000 83 Linux
/dev/sda3 1301 1497 1572864 82 Linux swap / Solaris
/dev/sda4 1497 3916 19436582 83 Linux
Command (m for help): wp #保存并退出，如果创建有误，直接退出不要保存即可The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
重新创建分区后，需要重启一下；
[root@linuxprobe ~]# init 6 [root@linuxprobe ~]# e2fsck -f /dev/sda4 #检查分区信息[root@linuxprobe ~]# resize2fs -p /dev/sda4 #调整分区大小
重新挂载、查看分区大小、数据
[root@linuxprobe ~]# mount /dev/sda4 /data [root@linuxprobe ~]# df -hT [root@linuxprobe ~]# cat /data/linuxprobe we are Linuxer
在vim修改/etc/fstab文件,加入【/dev/sda4 /disk4 ext2 defaults 0 0】一行，并保存，实现开机自动mount。
