lvm下缩小根分区

一/先查看当前的 根分区 大小为21G

[root@test-disk ~]# df -h

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/VolGroup00-LogVol00 21G 960M 19G 5% /

/dev/mapper/VolGroup00-LogVol02 7.6G 151M 7.3G 2% /home

/dev/hda1 99M 12M 82M 13% /boot

tmpfs 189M 0 189M 0% /dev/shm

二/插入系统光盘，启动后输入linux rescue进去救援模式，不要配置网络，不要让系统根挂载到/mnt/sysimage上，所以最后的界面选择“skip”





分别为：查看物理卷 查看卷组 查看逻辑卷 激活逻辑卷

三/开始减小根文件系统大小





四/减小根lv大小









此时得出LogVol00的LE数量为682，总的PE数量为956，大小32M，所以可以减少的大小为

（956-682）*32M=8768M





五/重启进去系统，再次查看根分区情况

[root@test-disk ~]# df -h

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/VolGroup00-LogVol00 13G 956M 12G 8% /

/dev/mapper/VolGroup00-LogVol02 7.6G 151M 7.3G 2% /home

/dev/hda1 99M 12M 82M 13% /boot

tmpfs 189M 0 189M 0% /dev/shm

[root@test-disk ~]# vgdisplay 查看卷组情况

--- Volume group ---

VG Name VolGroup00

System ID

Format lvm2

Metadata Areas 1

Metadata Sequence No 10

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 29.88 GB

PE Size 32.00 MB

Total PE 956

Alloc PE / Size 682 / 21.31 GB

Free PE / Size 274 / 8.56 GB

VG UUID l6vUxv-U8KC-gVdH-RQH5-QuUC-jsdl-HjpVqN

[root@test-disk ~]# lvdisplay /dev/VolGroup00/LogVol00

--- Logical volume ---

LV Name /dev/VolGroup00/LogVol00

VG Name VolGroup00

LV UUID Nbcfw3-7jG7-URyG-fRdl-5k6j-x0BC-EFpt0J

LV Write Access read/write

LV Status available

# open 1

LV Size 12.75 GB

Current LE 408

Segments 1

Allocation inherit

Read ahead sectors auto

- currently set to 256

Block device 253:0

六/把从根分区减出的添加到/home

[root@test-disk ~]# umount /home/

[root@test-disk ~]# e2fsck -f /dev/VolGroup00/LogVol02

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/VolGroup00/LogVol02: 11/2064384 files (9.1% non-contiguous), 103072/2048000 blocks

[root@test-disk ~]# lvextend -l +274 /dev/VolGroup00/LogVol02

/dev/cdrom: open failed: Read-only file system

Extending logical volume LogVol02 to 16.38 GB

Logical volume LogVol02 successfully resized

[root@test-disk ~]# e2fsck -f /dev/VolGroup00/LogVol02

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/VolGroup00/LogVol02: 11/2064384 files (9.1% non-contiguous), 103072/2048000 blocks

[root@test-disk ~]# resize2fs /dev/VolGroup00/LogVol02

resize2fs 1.39 (29-May-2006)

Resizing the filesystem on /dev/VolGroup00/LogVol02 to 4292608 (4k) blocks.

The filesystem on /dev/VolGroup00/LogVol02 is now 4292608 blocks long.

[root@test-disk ~]# mount -a

[root@test-disk ~]# df -h 再次查看，成功

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/VolGroup00-LogVol00 13G 956M 12G 8% /

/dev/hda1 99M 12M 82M 13% /boot

tmpfs 189M 0 189M 0% /dev/shm

/dev/mapper/VolGroup00-LogVol02 16G 155M 16G 1% /home