使用命令行工具实施 LVM 存储

[root@server8 ~]# fdisk -cu /dev/vdb

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First sector (2048-10485759, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-10485759, default 10485759): +500M

Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 8e
Changed system type of partition 1 to 8e (Linux LVM)

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
[root@server8 ~]# cat /proc/partitions
major minor  #blocks  name

 252        0    8388608 vda
 252        1     512000 vda1
 252        2    7875584 vda2
 252       16    5242880 vdb
 252       17     512000 vdb1
 253        0    6856704 dm-0
 253        1    1015808 dm-1

[root@server8 ~]# pvcreate /dev/vdb1  将物理存储打为pv

[root@server8 ~]# vgcreate newvg /dev/vdb1将PV打为VG
  Volume group "newvg" successfully created
[root@server8 ~]# lvcreate -n newlv -L 200M newvg -L为最终大小  -n后接LV名字
  Logical volume "newlv" created
[root@server8 ~]# mkfs -t ext4 /dev/mapper/newvg-newlv 格式化
[root@server8 ~]# mkdir /lv
[root@server8 ~]# mount /dev/mapper/newvg-newlv /lv手动挂载
[root@server8 ~]# vi /etc/fstab 开机自动挂载
/dev/mapper/newvg-newlv /lv    ext4   defaults  0  0
[root@server8 ~]# umount /lv
[root@server8 ~]# mount -a
[root@server8 ~]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/vg_server8-lv_root
                       6748936   1331260   5074844  21% /
tmpfs                   498072         0    498072   0% /dev/shm
/dev/vda1               495844     31932    438312   7% /boot
/dev/mapper/newvg-newlv
                        198337      5646    182451   4% /lv

扩展逻辑卷和 Ext4 文件系统

[root@server8 ~]# lvextend -L +100M /dev/mapper/newvg-newlv 拉伸LV

[root@server8 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_server8-lv_root
                      6.5G  1.3G  4.9G  21% /
tmpfs                 487M     0  487M   0% /dev/shm
/dev/vda1             485M   32M  429M   7% /boot
/dev/mapper/newvg-newlv
                      194M  5.6M  179M   4% /lv
[root@server8 ~]# resize2fs -p /dev/mapper/newvg-newlv拉伸文件系统
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/newvg-newlv is mounted on /lv; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 2
Performing an on-line resize of /dev/mapper/newvg-newlv to 307200 (1k) blocks.
The filesystem on /dev/mapper/newvg-newlv is now 307200 blocks long.

[root@server8 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_server8-lv_root
                      6.5G  1.3G  4.9G  21% /
tmpfs                 487M     0  487M   0% /dev/shm
/dev/vda1             485M   32M  429M   7% /boot
/dev/mapper/newvg-newlv
                      291M  6.1M  270M   3% /lv

缩减LVS

[root@server8 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_server8-lv_root
                      6.5G  1.3G  4.9G  21% /
tmpfs                 487M     0  487M   0% /dev/shm
/dev/vda1             485M   32M  429M   7% /boot
/dev/mapper/newvg-newlv
                      291M  6.1M  270M   3% /lv
1.[root@server8 ~]# umount /lv  卸载
[root@server8 ~]# lvs
  LV      VG         Attr     LSize   Pool Origin Data%  Move Log Copy%  Convert
  newlv   newvg      -wi-a--- 300.00m
  lv_root vg_server8 -wi-ao--   6.54g
  lv_swap vg_server8 -wi-ao-- 992.00m
2，[root@server8 ~]# fsck -f /dev/mapper/newvg-newlv   以在进行大小调整之前验证所有文件系统数据结构是否都已得到清理
fsck from util-linux-ng 2.17.2
e2fsck 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/newvg-newlv: 11/77824 files (0.0% non-contiguous), 15979/307200 blocks
[root@server8 ~]# resize2fs /dev/mapper/newvg-newlv 200M  会将文件系统大小调整为200M ,假设逻辑卷大于 200M 。
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/mapper/newvg-newlv to 204800 (1k) blocks.
The filesystem on /dev/mapper/newvg-newlv is now 204800 blocks long.

[root@server8 ~]# lvreduce -L 200 /dev/mapper/newvg-newlv   会将逻辑卷减小到200M
  WARNING: Reducing active logical volume to 200.00 MiB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce newlv? [y/n]: y
  Reducing logical volume newlv to 200.00 MiB
  Logical volume newlv successfully resized
[root@server8 ~]# mount -a
[root@server8 ~]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/vg_server8-lv_root
                       6748936   1331836   5074268  21% /
tmpfs                   498072         0    498072   0% /dev/shm
/dev/vda1               495844     31932    438312   7% /boot
/dev/mapper/newvg-newlv
                        198337      5646    182457   4% /lv
[root@server8 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_server8-lv_root
                      6.5G  1.3G  4.9G  21% /
tmpfs                 487M     0  487M   0% /dev/shm
/dev/vda1             485M   32M  429M   7% /boot
/dev/mapper/newvg-newlv
                      194M  5.6M  179M   4% /lv