1        在vmware安裝系統的時候使用了系統的自動分割槽，系統裝好後發現/home分割槽太大了30G，使得/root下不夠用。需將/home的空間劃一點出來，分到根分割槽下去。

1.檢視分割槽資訊#df  -h

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                       50G  7.7G   39G  17% /
tmpfs                 932M  292K  932M   1% /dev/shm
/dev/sda1             477M   42M  410M  10% /boot
/dev/mapper/VolGroup-lv_home
                       33G  348M   31G   2% /home
.host:/                98G   64G   35G  66% /mnt/hgfs
/dev/sr0              3.7G  3.7G     0 100% /media/RHEL-6.8 Server.x86_64

2.解除安裝/home

#umount /home

3.調整/home大小為20G

# resize2fs -p /dev/mapper/VolGroup-lv_home 20G

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

注：如果出現上面提示，請執行#e2fsce2fsck 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/VolGroup-lv_home: 4372/2203648 files (0.2% non-contiguous), 260035/8808448 blocks
k -f /dev/mapper/VolGroup-lv_home

繼續執行#resize2fs -p /dev/mapper/VolGroup-lv_home 20G

resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/mapper/VolGroup-lv_home to 5242880 (4k) blocks.
Begin pass 2 (max = 53699)
Relocating blocks             XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 3 (max = 269)
Scanning inode table          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 4 (max = 985)
Updating inode references     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The filesystem on /dev/mapper/VolGroup-lv_home is now 5242880 blocks long.

4.掛載/home後並df檢視大小

#mount /home

#df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                       50G  7.7G   39G  17% /
tmpfs                 932M  292K  932M   1% /dev/shm
/dev/sda1             477M   42M  410M  10% /boot
.host:/                98G   64G   35G  66% /mnt/hgfs
/dev/sr0              3.7G  3.7G     0 100% /media/RHEL-6.8 Server.x86_64
/dev/mapper/VolGroup-lv_home
                       20G  344M   19G   2% /home

5.收縮/home大小為20G，釋放其餘空間。需按y確認

#lvreduce -L 20G /dev/mapper/VolGroup-lv_home

WARNING: Reducing active and open logical volume to 20.00 GiB.
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce VolGroup/lv_home? [y/n]: y
  Size of logical volume VolGroup/lv_home changed from 33.60 GiB (8602 extents) to 20.00 GiB (5120 extents).
  Logical volume lv_home successfully resized.

6.查剩餘空間大小

#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               87.51 GiB
  PE Size               4.00 MiB
  Total PE              22402
  Alloc PE / Size       18920 / 73.91 GiB
  Free  PE / Size       3482 / 13.60 GiB
  VG UUID               k74r18-xXPi-2sVI-JUYn-QZuF-8JcC-OcZ28W

7.將剩餘空間劃分到/目錄下，即/dev/mapper/VolGroup-lv_root

#lvextend -L +13G /dev/mapper/VolGroup-lv_root

Size of logical volume VolGroup/lv_root changed from 50.00 GiB (12800 extents) to 63.00 GiB (16128 extents).
  Logical volume lv_root successfully resized.

8.重新設定/分割槽大小，使擴充套件的空間生效
[[email protected] hyl]# 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 = 4
Performing an on-line resize of /dev/mapper/VolGroup-lv_root to 16515072 (4k) blocks.
The filesystem on /dev/mapper/VolGroup-lv_root is now 16515072 blocks long.

9.檢視確認分割槽大小
# df -h

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                       62G  7.8G   52G  14% /
tmpfs                 932M  292K  932M   1% /dev/shm
/dev/sda1             477M   42M  410M  10% /boot
.host:/                98G   64G   35G  66% /mnt/hgfs
/dev/sr0              3.7G  3.7G     0 100% /media/RHEL-6.8 Server.x86_64
/dev/mapper/VolGroup-lv_home
                       20G  344M   19G   2% /home

至此，完成了將/home的空間分到/root下的操作。