缩小LVM分区大小

[root@RHEL ~]# df -lh    #显示当前各个分区的使用情况
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg-root   992M  181M  760M  20% /
/dev/mapper/vg-usr    2.0G  787M  1.1G  42% /usr
/dev/mapper/vg-var    2.0G   86M  1.8G   5% /var
/dev/sda1              99M   12M   82M  13% /boot
tmpfs                 125M     0  125M   0% /dev/shm
/dev/mapper/vg-home   992M   11M  930M   2% /home

 

[root@RHEL ~]# umount /dev/vg/home    #卸载/dev/vg/home

 

[root@RHEL ~]# e2fsck -f /dev/vg/home    #强制检查/dev/vg/home文件系统的正确性
e2fsck 1.39 (29-May-2006)
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/vg/home: 17/262144 files (17.6% non-contiguous), 44125/1048576 blocks

 

[root@RHEL ~]# resize2fs /dev/vg/home 256M    #先缩小/dev/vg/home文件系统的大小
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/vg/home to 262144 (1k) blocks.
The filesystem on /dev/vg/home is now 262144 blocks long.
--------------------------------------------------------------------
resize2fs 程序可以更改ext2/ext3文件系统。它可以放大和缩小它能够找到的设备上的被umount掉的文件系统。如果文件系统是处于mount状态下，那么它只能做到扩容，前提条件是内核支持在线resize(linux kernel2.6支持在mount状态下扩容但仅限于ext3文件系统)。
--------------------------------------------------------------------

 

[root@RHEL ~]# lvresize -L 256M /dev/vg/home    #缩小/dev/vg/home的LVM大小
  WARNING: Reducing active logical volume to 256.00 MB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce home? [y/n]: y
  Reducing logical volume home to 256.00 MB
  Logical volume home successfully resized

 

[root@RHEL ~]# mount -a

 

[root@RHEL ~]# df -lh
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg-root   992M  181M  760M  20% /
/dev/mapper/vg-usr    2.0G  787M  1.1G  42% /usr
/dev/mapper/vg-var    2.0G   86M  1.8G   5% /var
/dev/sda1              99M   12M   82M  13% /boot
tmpfs                 125M     0  125M   0% /dev/shm
/dev/mapper/vg-home   248M   11M  228M   5% /home