centos下如何使用fdisk扩展分区容量大小
扩展磁盘空间
硬盘空间为20G，使用vSphere Client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；
[root@linuxprobe ~]# fdisk -lDisk /dev/sda: 32.2 GB, 32212254720 bytes255 heads, 63 sectors/track, 3916 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x0005210c Device Boot Start End Blocks Id System/dev/sda1 * 1 26 204800 83 LinuxPartition 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[root@linuxprobe ~]# df -hTFilesystem Type Size Used Avail Use% Mounted on/dev/sda2 ext4 9.7G 1.5G 7.7G 16% /tmpfs tmpfs 939M 0 939M 0% /dev/shm/dev/sda1 ext4 194M 34M 151M 19% /boot/dev/sda4 ext4 8.5G 148M 7.9G 2% /data
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]# lltotal 24-rw-r--r--. 1 root root 15 May 23 21:59 linuxprobedrwx------. 2 root root 16384 May 23 15:07 lost+founddrwxr-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 /datafuser -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/sdaWARNING: 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 bytes255 heads, 63 sectors/track, 3916 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x0005210c Device Boot Start End Blocks Id System/dev/sda1 * 1 26 204800 83 LinuxPartition 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 LinuxCommand (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 bytes255 heads, 63 sectors/track, 3916 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x0005210c Device Boot Start End Blocks Id System/dev/sda1 * 1 26 204800 83 LinuxPartition 1 does not end on cylinder boundary./dev/sda2 26 1301 10240000 83 Linux/dev/sda3 1301 1497 1572864 82 Linux swap / SolarisCommand (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 4First 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 1497Last 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 bytes255 heads, 63 sectors/track, 3916 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x0005210c Device Boot Start End Blocks Id System/dev/sda1 * 1 26 204800 83 LinuxPartition 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 LinuxCommand (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 atthe 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/linuxprobewe are Linuxer
