昨天接到客户机器系统盘磁盘满，本想将数据迁移到home目录，但是系统盘数据大小和home磁盘容量基本相同，于是打算做迁移，考虑将home容量划分到系统盘下，以下是操作教程。
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 50G 47G 16M 100% / //lv_root满了 tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 485M 40M 420M 9% /boot
/dev/mapper/VolGroup-lv_home 406G 19G 366G 5% /home //lv_home空间很多
[root@localhost ~]# resize2fs -p /dev/mapper/VolGroup-lv_home 100G
resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/mapper/VolGroup-lv_home is mounted on /home; on-line resizing required
On-line shrinking from 107865088 to 65536000 not supported. //先umount才能resize2fs
[root@localhost ~]# umount /home //umount home目录
[root@localhost ~]# resize2fs -p /dev/mapper/VolGroup-lv_home 100G
resize2fs 1.41.12 (17-May-2010) 请先运行 'e2fsck -f /dev/mapper/VolGroup-lv_home'. //提示要先进行磁盘检测
[root@localhost ~]# e2fsck -f /dev/mapper/VolGroup-lv_home
e2fsck 1.41.12 (17-May-2010) 第一步: 检查inode,块,和大小
第二步: 检查目录结构
第3步: 检查目录连接性
Pass 4: Checking reference counts
第5步: 检查簇概要信息
/dev/mapper/VolGroup-lv_home: 1459/16384000 files (4.0% non-contiguous), 5914204/65536000 blocks
[root@localhost ~]# resize2fs -p /dev/mapper/VolGroup-lv_home 100G //重定大小 resize2fs 1.41.12 (17-May-2010) Resizing the filesystem on /dev/mapper/VolGroup-lv_home to 26214400 (4k) blocks. Begin pass 2 (max = 32768) 正在重定位块 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 3 (max = 2000) 正在扫描inode表 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The filesystem on /dev/mapper/VolGroup-lv_home is now 26214400 blocks long.
[root@localhost ~]# mount /home/
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 50G 47G 16M 100% / tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 485M 40M 420M 9% /boot
/dev/mapper/VolGroup-lv_home 99G 19G 75G 20% /home
[root@localhost ~]# lvreduce -L 100G /dev/mapper/VolGroup-lv_home //释放空间
WARNING: Reducing active and open logical volume to 100.00 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 100.00 GiB
Logical volume lv_home successfully resized
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 50G 47G 16M 100% / tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 485M 40M 420M 9% /boot
/dev/mapper/VolGroup-lv_home 99G 19G 75G 20% /home
[root@localhost ~]# vgdisplay
--- Volume group ---
VG Name VolGroup
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 465.27 GiB
PE Size 4.00 MiB
Total PE 119109
Alloc PE / Size 39372 / 153.80 GiB
Free PE / Size 79737 / 311.47 GiB //空闲空间
VG UUID Vt2V4t-Byxs-tQqk-cY0h-IDE3-pabX-LUfkRS
[root@localhost ~]# lvextend -L +311.47G /dev/mapper/VolGroup-lv_root //空闲空间加入到lv_root
Rounding size to boundary between physical extents: 311.47 GiB
Extending logical volume lv_root to 361.47 GiB
Logical volume lv_root successfully resized
[root@localhost ~]# resize2fs -p /dev/mapper/VolGroup-lv_root
resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/mapper/VolGroup-lv_root is mounted on /; on-line resizing required
old desc_blocks = 4, new_desc_blocks = 23 //这儿要耐心等待，扩大越多，时间越长 Performing an on-line resize of /dev/mapper/VolGroup-lv_root to 94757888 (4k) blocks. The filesystem on /dev/mapper/VolGroup-lv_root is now 94757888 blocks long.
[root@localhost openfire]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 356G 48G 308G 14% / tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 485M 40M 420M 9% /boot
/dev/mapper/VolGroup-lv_home 99G 19G 75G 20% /home
