在我看來使用lvm的好處有兩個：可以很方便地動態expand/shrink分區大小；不受分區個數的限制。
在howtoforge網站有非常好的lvm使用的介紹：http://www.howtoforge.com/linux_lvm
這裏記錄自己的操作過程：
1.使用pvcreate創建physical volumn
[root@jcwkyl ~]# fdisk -l
Disk /dev/sda: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot
Start
End Blocks Id System
/dev/sda1
*
1
13 104391 83 Linux
/dev/sda2
14 6540
52428127+ 83 Linux
/dev/sda3
6541 13067
52428127+ 83 Linux
/dev/sda4
13068 38913
207607995 8e Linux LVM
[root@jcwkyl ~]# pvcreate /dev/sda4
Physical volume "/dev/sda4" successfully created
2.使用vgcreate創建volumn group
[root@jcwkyl ~]# vgcreate xen_space /dev/sda4
Volume group "xen_space" successfully created
3.使用lvcreate創建logical volumn
[root@jcwkyl ~]# lvcreate -n image_pool -L 100G xen_space
Logical volume "image_pool" created
[root@jcwkyl ~]# lvcreate -n swap -L 5G xen_space
Logical volume "swap" created
4.在新創建的logical volumn上創建文件系統，並掛載使用
[root@jcwkyl ~]# mkfs.ext3 /dev/xen_space/image_pool
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
13107200 inodes, 26214400 blocks
1310720 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
800 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872
Writing
inode tables:
done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 27 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@jcwkyl ~]# mount /dev/xen_space/image_pool /vm
在/etc/fstab中加入下面一條記錄，使得每次開機時自動mount相應的分區：
/dev/xen_space/image_pool
/vm
ext3
defaults 0 0
