Linux下如何调整根目录的空间大小

Linux下如何调整根目录的空间大小

一、目的

在使用CentOS6.3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：

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01.[root@CentOS-78 /]# df -h

02.Filesystem Size Used Avail Use% Mounted on

03./dev/mapper/vg_centos-lv_root

04. 50G 14G 34G 30% /

05.tmpfs 1.9G 0 1.9G 0% /dev/shm

06./dev/sda1 485M 37M 423M 8% /boot

07./dev/mapper/vg_centos-lv_home

08. 404G 670M 382G 1% /home

下面的详细步骤部分将从vg_centos-lv_home分区下取出100G的空间添加到/vg_centos-lv_root分区上去。

二、详细步骤

1、卸载vg_centos-lv_home分区

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01.[root@CentOS-78 /]# 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：

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01.[root@CentOS-78 /]# df -h

02.Filesystem Size Used Avail Use% Mounted on

03./dev/mapper/vg_centos-lv_root

04. 50G 14G 34G 30% /

05.tmpfs 1.9G 0 1.9G 0% /dev/shm

06./dev/sda1 485M 37M 423M 8% /boot

2、从新设定vg_home-lv_home的大小

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01.[root@CentOS-78 /]# resize2fs -p /dev/mapper/vg_centos-lv_home 282G

02.resize2fs 1.41.12 (17-May-2010)

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

这一步设定vg_home-lv_home大小没有成功，系统提示我们先运行下面的命令，操作如下：

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01.[root@CentOS-78 /]# e2fsck -f /dev/mapper/vg_centos-lv_home

02.e2fsck 1.41.12 (17-May-2010)

03.Pass 1: Checking inodes, blocks, and sizes

04.Pass 2: Checking directory structure

05.Pass 3: Checking directory connectivity

06.Pass 4: Checking reference counts

07.Pass 5: Checking group summary information

08./dev/mapper/vg_centos-lv_home: 1386/26836992 files (0.9% non-contiguous), 1855856/107344896 blocks

从新设定vg_home-lv_home的大小：

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01.[root@CentOS-78 /]# resize2fs -p /dev/mapper/vg_centos-lv_home 282G

02.resize2fs 1.41.12 (17-May-2010)

03.Resizing the filesystem on /dev/mapper/vg_centos-lv_home to 73924608 (4k) blocks.

04.Begin pass 2 (max = 43)

05.Relocating

blocks XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

06.Begin pass 3 (max = 3276)

07.Scanning inode table XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

08.Begin pass 4 (max = 266)

09.Updating

inodereferences XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

10.The filesystem on /dev/mapper/vg_centos-lv_home is now 73924608 blocks long.

检查是否成功：

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01.[root@CentOS-78 /]# mount /home

02.[root@CentOS-78 /]#

03.[root@CentOS-78 /]# df -h

04.Filesystem Size Used Avail Use% Mounted on

05./dev/mapper/vg_centos-lv_root

06. 50G 14G 34G 30% /

07.tmpfs 1.9G 0 1.9G 0% /dev/shm

08./dev/sda1 485M 37M 423M 8% /boot

09./dev/mapper/vg_centos-lv_home

10. 278G 663M 263G 1% /home

11.[root@CentOS-78 /]#

3、将lv_home逻辑分区减小到指定大小

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01.[root@CentOS-78 /]#lvreduce -L 282G /dev/mapper/vg_centos-lv_home

02. WARNING: Reducing active and open logical volume to 282.00 GiB

03. THIS MAY DESTROY YOUR DATA (filesystem etc.)

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

05. Reducing logical volume lv_home to 282.00 GiB

06. Logical volume lv_home successfully resized

07.[root@CentOS-78 /]#

我认为这个命令是将已经减少的100G空间拿到系统公共的区域，可以被其他分区加载和利用。

查询卷组的信息：

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01.[root@CentOS-78 /]# vgdisplay

02. --- Volume group ---