Linux下调整目录的空间大小

一、目的

在使用CentOS6.5版本linux系统的时候，发现根目录(/)的空间不是很充足，而其他目录空间有很大的空闲，所以本文主要是针对现在已有的空间进行调整。首先，先来查看一下系统的空间分配情况：
[root@innoplay01 ~]# lsb_release -a

LSB Version: :base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch

Distributor ID: CentOS

Description: CentOS release 6.5 (Final)

Release: 6.5

Codename: Final

[root@innoplay01 java]# df -h

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/vg_innoplay01-lv_root 50G 2.0G 45G 5% /

tmpfs 3.9G 0 3.9G 0% /dev/shm

/dev/sda1 485M 40M 421M 9% /boot

/dev/mapper/vg_innoplay01-lv_home 860G 200M 816G 1% /home

下面的详细步骤部分将从/dev/mapper/vg_innoplay01-lv_home 分区下取出661G的空间添加到/dev/mapper/vg_innoplay01-lv_root 分区上去。

卸载/dev/mapper/vg_innoplay01-lv_home分区:

[root@innoplay01 java]# umount /home

此时在用df命令查看将会发现/home目录已经看不见了，如下所示：

[root@innoplay01 java]# df -h

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/vg_innoplay01-lv_root 50G 2.0G 45G 5% /

tmpfs 3.9G 0 3.9G 0% /dev/shm

/dev/sda1 485M 40M 421M 9% /boot



从新设定/dev/mapper/vg_innoplay01-lv_home的大小:

resize2fs -p /dev/mapper/vg_innoplay01-lv_home 210G

[root@innoplay01 java]# resize2fs -p /dev/mapper/vg_innoplay01-lv_home 210G

resize2fs 1.41.12 (17-May-2010)

Please run 'e2fsck -f /dev/mapper/vg_innoplay01-lv_home' first.

依照提示执行：

e2fsck -f /dev/mapper/vg_innoplay01-lv_home

[root@innoplay01 java]# e2fsck -f /dev/mapper/vg_innoplay01-lv_home

e2fsck 1.41.12 (17-May-2010)

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/mapper/vg_innoplay01-lv_home: 11/57237504 files (0.0% non-contiguous), 3643567/228918272 blocks

[root@innoplay01 java]# resize2fs -p /dev/mapper/vg_innoplay01-lv_home 210G

resize2fs 1.41.12 (17-May-2010)

Resizing the filesystem on /dev/mapper/vg_innoplay01-lv_home to 55050240 (4k) blocks.

Begin pass 2 (max = 32768)

Relocating blocks XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Begin pass 3 (max = 6987)

Scanning inode table XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

The filesystem on /dev/mapper/vg_innoplay01-lv_home is now 55050240 blocks long.



检查是否成功：

[root@innoplay01 java]# mount /home

[root@innoplay01 java]# df -h

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/vg_innoplay01-lv_root 50G 2.0G 45G 5% /

tmpfs 3.9G 0 3.9G 0% /dev/shm

/dev/sda1 485M 40M 421M 9% /boot

/dev/mapper/vg_innoplay01-lv_home 207G 188M 197G 1% /home

将/dev/mapper/vg_innoplay01-lv_home逻辑分区减小到指定大小：

lvreduce -L 210G /dev/mapper/vg_innoplay01-lv_home

[root@innoplay01 java]# lvreduce -L 210G /dev/mapper/vg_innoplay01-lv_home

WARNING: Reducing active and open logical volume to 210.00 GiB

THIS MAY DESTROY YOUR DATA (filesystem etc.)

Do you really want to reduce lv_home? [y/n]: y

Reducing logical volume lv_home to 210.00 GiB

Logical volume lv_home successfully resized

查询卷组的信息：

vgdisplay

[root@innoplay01 java]# vgdisplay

--- Volume group ---

VG Name vg_innoplay01

System ID

Format lvm2

Metadata Areas 1

Metadata Sequence No 5

VG Access read/write

VG Status resizable

MAX LV 0

Cur LV 3

Open LV 3

Max PV 0

Cur PV 1

Act PV 1

VG Size 931.02 GiB

PE Size 4.00 MiB

Total PE 238341

Alloc PE / Size 68548 / 267.77 GiB

Free PE / Size 169793 / 663.25 GiB

VG UUID SyMjnp-iGwM-MkT1-UBUM-rSx8-hviz-EzTUEr

Free PE / Size指定的应该是现在可在分配的空间。

增加/dev/mapper/vg_innoplay01-lv_root分区的大小:

lvextend -L +661.00G /dev/mapper/vg_innoplay01-lv_root

[root@innoplay01 java]# lvextend -L +661.00G /dev/mapper/vg_innoplay01-lv_root

Extending logical volume lv_root to 711.00 GiB

Logical volume lv_root successfully resized

从新设定该分区的大小：

resize2fs -p /dev/mapper/vg_innoplay01-lv_root

[root@innoplay01 java]# resize2fs -p /dev/mapper/vg_innoplay01-lv_root

resize2fs 1.41.12 (17-May-2010)

Filesystem at /dev/mapper/vg_innoplay01-lv_root is mounted on /; on-line resizing required

old desc_blocks = 18, new_desc_blocks = 45

Performing an on-line resize of /dev/mapper/vg_innoplay01-lv_root to 186384384 (4k) blocks.

The filesystem on /dev/mapper/vg_innoplay01-lv_root is now 186384384 blocks long.

再次查看分区大小:

[root@innoplay01 java]# df -h

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/vg_innoplay01-lv_root 700G 2.0G 663G 1% /

tmpfs 3.9G 0 3.9G 0% /dev/shm

/dev/sda1 485M 40M 421M 9% /boot

/dev/mapper/vg_innoplay01-lv_home 207G 188M 197G 1% /home

注意点：

1、在卸载/home目录的时候失败，可先执行如下fuser命令，然后再umount即可：fuser -m /home ；

2、设定完lv_home的大小，再次mount该分区时，发现用df命令无法看到给分区，此时只要在mount一次即可；

3、在设定lv_root的大小时，不要把Free PE / Size的空间全部都用上，这很可能会出现Free PE空间不足的现象，建议保留一点Free PE的空间。