Centos6.5调整同一VG下两个LV空间

实验目的：

调整前

lv_root分区大小为50G

Lv_home分区大小为45G

 

调整后（将lv_home分区减小30G，将30G空间加到lv_root分区）

lv_root分区大小为80G

Lv_home分区大小为15G

 

操做前注意备份重要数据

1     查看磁盘使用状况

[root@lvm ~]# df –h

Filesystem                  Size  Used Avail Use% Mounted on /dev/mapper/vg_lvm-lv_root   50G  769M   46G   2% / tmpfs                       1.9G     0  1.9G   0% /dev/shm /dev/sda1                   485M   33M  427M   8% /boot /dev/mapper/vg_lvm-lv_home   45G  180M   43G   1% /home

2     卸载/home

[root@lvm ~]# umount /home [root@lvm ~]# df -h

Filesystem                  Size  Used Avail Use% Mounted on /dev/mapper/vg_lvm-lv_root   50G  769M   46G   2% / tmpfs                       1.9G     0  1.9G   0% /dev/shm /dev/sda1                   485M   33M  427M   8% /boot

注意：umount /home 若是提示没法卸载，则是有进程占用/home，使用以下命令来终止占用进程：

[root@lvm ~]# fuser -m /home

3     调整lv_home分区大小

[root@lvm ~]# resize2fs -p /dev/mapper/vg_lvm-lv_home 15G

resize2fs 1.41.12 (17-May-2010) Please run 'e2fsck -f /dev/mapper/vg_lvm-lv_home' first.

[root@lvm ~]# e2fsck -f /dev/mapper/vg_lvm-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_lvm-lv_home: 12/2992416 files (0.0% non-contiguous), 233858/11962368 blocks

[root@lvm ~]# resize2fs -p /dev/mapper/vg_lvm-lv_home 15G

resize2fs 1.41.12 (17-May-2010) Resizing the filesystem on /dev/mapper/vg_lvm-lv_home to 3932160 (4k) blocks. Begin pass 2 (max = 32769) Relocating blocks             XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Begin pass 3 (max = 366) Scanning inode table          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Begin pass 4 (max = 6) Updating inode references     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX The filesystem on /dev/mapper/vg_lvm-lv_home is now 3932160 blocks long.

注：resize2fs 为从新设定磁盘大小，只是从新指定一下大小，并不对结果有影响，须要下面lvreduce的配合

4     挂载/home查看使用状况

[root@lvm ~]# mount /dev/mapper/vg_lvm-lv_home /home [root@lvm ~]# df -h

Filesystem                  Size  Used Avail Use% Mounted on /dev/mapper/vg_lvm-lv_root   50G  769M   46G   2% / tmpfs                       1.9G     0  1.9G   0% /dev/shm /dev/sda1                   485M   33M  427M   8% /boot /dev/mapper/vg_lvm-lv_home   15G  168M   14G   2% /home

5     设置空闲空间

使用lvreduce指令用于减小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，因此在操做前必须进行确认。记得输入 “y

[root@lvm ~]# lvreduce -L 15G /dev/mapper/vg_lvm-lv_home

WARNING: Reducing active and open logical volume to 15.00 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 15.00 GiB   Logical volume lv_home successfully resized

注：lvreduce -L 15G的意思为设置当前文件系统为15G，若是lvreduce –l 15G是指从当前文件系统上减小15G

使用lvreduce减少逻辑卷的大小。注意：减少后的大小不能小于文件的大小，不然会丢失数据。 

能够使用vgdisplay命令等查看一下能够操做的大小。也能够是用fdisk -l命令查看详细信息。

[root@lvm ~]# vgdisplay

--- Volume group ---   VG Name               vg_lvm   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               99.51 GiB   PE Size               4.00 MiB   Total PE              25474   Alloc PE / Size       17632 / 68.88 GiB   Free  PE / Size       7842 / 30.63 GiB   VG UUID               NOS2vP-0HRm-eh9K-cHx1-ZnOS-45CA-SOvjGz

注：vgdisplay为显示LVM卷组的元数据信息

 

6     把闲置空间添加到lv_root

[root@lvm ~]# df -h

Filesystem                  Size  Used Avail Use% Mounted on /dev/mapper/vg_lvm-lv_root   50G  769M   46G   2% / tmpfs                       1.9G     0  1.9G   0% /dev/shm /dev/sda1                   485M   33M  427M   8% /boot /dev/mapper/vg_lvm-lv_home   15G  168M   14G   2% /home

[root@lvm ~]# lvextend -L +30G /dev/mapper/vg_lvm-lv_root

Extending logical volume lv_root to 80.00 GiB   Logical volume lv_root successfully resized

注：lvextend -L +30G为在文件系统上增长30G

[root@lvm ~]# resize2fs -p /dev/mapper/vg_lvm-lv_root

执行后须要等待几分钟才能显示执行结果 resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/mapper/vg_lvm-lv_root is mounted on /; on-line resizing required old desc_blocks = 4, new_desc_blocks = 5 Performing an on-line resize of /dev/mapper/vg_lvm-lv_root to 20971520 (4k) blocks. The filesystem on /dev/mapper/vg_lvm-lv_root is now 20971520 blocks long.

7     查看调整结果

[root@lvm ~]# df -h

Filesystem                  Size  Used Avail Use% Mounted on /dev/mapper/vg_lvm-lv_root   79G  773M   74G   2% / tmpfs                       1.9G     0  1.9G   0% /dev/shm /dev/sda1                   485M   33M  427M   8% /boot /dev/mapper/vg_lvm-lv_home   15G  168M   14G   2% /home