linux(centos 6) 调整挂载分区大小

安装centos6使用自动推荐分区，发现一个问题/home 分区过大。

目标：/home分20G，剩下添加给/目录下

1.查看分区模式

1. [root@localhost ~]# df -h
2. 文件系统 容量 已用 可用 已用%% 挂载点
3. /dev/mapper/VolGroup-lv_root
4. 50G 2.9G 44G 7% /
5. tmpfs 5.9G 100K 5.9G 1% /dev/shm
6. /dev/sda1 485M 37M 423M 8% /boot
7. /dev/mapper/VolGroup-lv_home
8. 1.1T 200M 988G 1% /home

2.卸载挂载分区

1. [root@localhost ~]# umount /home

3.检查VolGroup-lv_home文件的错误性，-f 即使文件系统没有错误迹象，仍强制地检查正确性。

1. [root@localhost ~]# e2fsck -f /dev/mapper/VolGroup-lv_home
2. e2fsck 1.41.12 (17-May-2010)
3. 第一步: 检查inode,块,和大小
4. 第二步: 检查目录结构
5. 第3步: 检查目录连接性
6. Pass 4: Checking reference counts
7. 第5步: 检查簇概要信息
8. /dev/mapper/VolGroup-lv_home: 27/69304320 files (0.0% non-contiguous), 4400705/277215232 blocks

4.调整/home为20G，

1. [root@localhost ~]# resize2fs -p /dev/mapper/VolGroup-lv_home 20G
2. resize2fs 1.41.12 (17-May-2010)
3. Resizing the filesystem on /dev/mapper/VolGroup-lv_home to 5242880 (4k) blocks.
4. Begin pass 2 (max = 32784)
5. 正在重定位块 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
6. Begin pass 3 (max = 8460)
7. 正在扫描inode表 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
8. Begin pass 4 (max = 15)
9. 正在更新inode引用 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
10. The filesystem on /dev/mapper/VolGroup-lv_home is now 5242880 blocks long.

5.重新挂载并查看

1. [root@localhost ~]# mount /home
2. [root@localhost ~]# df -h
3. 文件系统 容量 已用 可用 已用%% 挂载点
4. /dev/mapper/VolGroup-lv_root
5. 50G 2.9G 44G 7% /
6. tmpfs 5.9G 100K 5.9G 1% /dev/shm
7. /dev/sda1 485M 37M 423M 8% /boot
8. /dev/mapper/VolGroup-lv_home
9. 20G 172M 19G 1% /home

6.划分20G外面的剩余空间。使用lvreduce指令用于减少LVM逻辑卷占用的空间大小。可能会删除逻辑卷上已有的数据，所以在操作前必须进行确认。记得输入 “y”

1. [root@localhost ~]# lvreduce -L 20G /dev/mapper/VolGroup-lv_home
2. WARNING: Reducing active and open logical volume to 20.00 GiB
3. THIS MAY DESTROY YOUR DATA (filesystem etc.)
4. Do you really want to reduce lv_home? [y/n]: y
5. Reducing logical volume lv_home to 20.00 GiB
6. Logical volume lv_home successfully resized

1. [root@localhost ~]# df -h
2. 文件系统 容量 已用 可用 已用%% 挂载点
3. /dev/mapper/VolGroup-lv_root
4. 50G 2.9G 44G 7% /
5. tmpfs 5.9G 100K 5.9G 1% /dev/shm
6. /dev/sda1 485M 37M 423M 8% /boot
7. /dev/mapper/VolGroup-lv_home
8. 20G 172M 19G 1% /home

7.查看“Free PE / Size”剩余空间

1. [root@localhost ~]# vgdisplay
2. --- Volume group ---
3. VG Name VolGroup
4. System ID
5. Format lvm2
6. Metadata Areas 1
7. Metadata Sequence No 5
8. VG Access read/write
9. VG Status resizable
10. MAX LV 0
11. Cur LV 3
12. Open LV 3
13. Max PV 0
14. Cur PV 1
15. Act PV 1
16. VG Size 1.09 TiB
17. PE Size 4.00 MiB
18. Total PE 285022
19. Alloc PE / Size 19424 / 75.88 GiB
20. Free PE / Size 265598 / 1.01 TiB
21. VG UUID nSbflh-J7fN-xDvf-zLjL-tFcu-Y5Tm-ybnDk0

8.使用lvextend指令：扩展逻辑卷空间到/dev/mapper/VolGroup-lv_root目录下，也就是“/”目录下。

1. [root@localhost ~]# lvextend -L +1.01T /dev/mapper/VolGroup-lv_root
2. Rounding size to boundary between physical extents: 1.01 TiB
3. Extending logical volume lv_root to 1.06 TiB
4. Logical volume lv_root successfully resized

9.执行操作，使之生效，中间一定要耐心等待。

1. [root@localhost ~]# resize2fs -p /dev/mapper/VolGroup-lv_root
2. resize2fs 1.41.12 (17-May-2010)
3. Filesystem at /dev/mapper/VolGroup-lv_root is mounted on /; on-line resizing required
4. old desc_blocks = 4, new_desc_blocks = 68
5. Performing an on-line resize of /dev/mapper/VolGroup-lv_root to 284227584 (4k) blocks.
6. The filesystem on /dev/mapper/VolGroup-lv_root is now 284227584 blocks long.

10.查看分区成功

1. [root@localhost ~]# df -h
2. 文件系统 容量 已用 可用 已用%% 挂载点
3. /dev/mapper/VolGroup-lv_root
4. 1.1T 2.9G 1011G 1% /
5. tmpfs 5.9G 100K 5.9G 1% /dev/shm
6. /dev/sda1 485M 37M 423M 8% /boot
7. /dev/mapper/VolGroup-lv_home
8. 20G 172M 19G 1% /home

11.重启

1. [root@localhost ~]# shutdown -r now

 安装操作系统的分区操作方案：

参见：http://wenku.baidu.com/view/1b1621d8d15abe23482f4d92.html