缩小LVM分区大小

来源：互联网发布：linux nagios 安装编辑：程序博客网时间：2024/05/01 18:46

[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.
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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)。
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[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