LVM的好处？
把物理存储设备的差异隐藏在LVM统一的接口之下。接口统一，管理方式统一，还可以进行动态卷扩展。
1、查看系统是否安装LVM
[root@localhost ~]# rpm -qa|grep lvm
lvm2-2.02.56-8.el5
system-config-lvm-1.1.5-4.el5
2、查看新添加的硬盘
[root@localhost ~]# fdisk -l
Disk /dev/sda: 322.1 GB, 322122547200 bytes
255 heads, 63 sectors/track, 39162 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 25 200781 83 Linux
/dev/sda2 26 13079 104856255 83 Linux
/dev/sda3 13080 26133 104856255 83 Linux
/dev/sda4 26134 39162 104655442+ 5 Extended
/dev/sda5 26134 34488 67111506 82 Linux swap / Solaris
/dev/sda6 34489 39162 37543873+ 83 Linux
Disk /dev/sdb: 1099.5 GB, 1099511627776 bytes
255 heads, 63 sectors/track, 133674 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdb doesn't contain a valid partition table
Disk /dev/sdc: 1924.1 GB, 1924145348608 bytes
255 heads, 63 sectors/track, 233930 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdc doesn't contain a valid partition table
Disk /dev/sdb: 1099.5 GB, 1099511627776 bytes
Disk /dev/sdc: 1924.1 GB, 1924145348608 bytes
这两个为新添加的硬盘
3、用fdisk分区(不创建分区也可以)
[root@localhost ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.
The number of cylinders for this disk is set to 133674.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): n 这里输入n
Command action
e extended
p primary partition (1-4)
p 这里输入p
Partition number (1-4): 4 这里输入4
First cylinder (1-133674, default 1): 回车
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-133674, default 133674): 回车
Using default value 133674
Command (m for help): w 这里输入w保存
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
两块硬盘都要分区 /dev/sdb /dev/sdc
4、创建PV ( pvcreate )
[root@localhost ~]# pvcreate /dev/sdb4 /dev/sdc4 --或 pvcreate /dev/sdb /dev/sdc
Physical volume "/dev/sdb4" successfully created
Physical volume "/dev/sdc4" successfully created
5、查看PV信息
[root@localhost ~]# pvscan
PV /dev/sdb4 lvm2 [1023.99 GB]
PV /dev/sdc4 lvm2 [1.75 TB]
Total: 2 [2.75 TB] / in use: 0 [0 ] / in no VG: 2 [2.75 TB]
6、创建VG
[root@localhost ~]# vgcreate mailvg /dev/sdb4 /dev/sdc4 --或 vgcreate mailvg /dev/sdb /dev/sdc
Volume group "mailvg" successfully created
注：VG的名子是 mailvg 这一步是把 /dev/sdb4 /dev/sdc4是把这两个分区都添加到mailvg这个VG里
7、查看VG
[root@localhost ~]# vgdisplay
--- Volume group ---
VG Name mailvg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 2.75 TB
PE Size 4.00 MB
Total PE 720892
Alloc PE / Size 0 / 0
Free PE / Size 720892 / 2.75 TB
VG UUID aUVOo4-2b75-1nuR-Ppll-G3AT-Rap8-jANOJ3
可以看到 两个分区加到一起一共是 2.75TB
8、创建LV
可以创建多个LV本例把所有容量只创建一个大的LV
[root@localhost ~]# lvcreate -L 2.749T -n mailvg01 mailvg
Rounding up size to full physical extent 2.75 TB
Logical volume "mailvg01" created
2.749T为这个LV的容量 mailvg01是LV的名子 mailvg是VG的名子
9、扫描 lv 逻辑单元
[root@localhost ~]# lvscan
ACTIVE '/dev/mailvg/mailvg01' [2.75 TB] inherit
10、查看LV信息
[root@localhost ~]# lvdisplay /dev/mailvg/mailvg01
--- Logical volume ---
LV Name /dev/mailvg/mailvg01
VG Name mailvg
LV UUID ucGT0x-FX0M-OTWM-6UEu-utpE-kjOD-huCSDr
LV Write Access read/write
LV Status available
# open 0
LV Size 2.75 TB
Current LE 720634
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
11、格式化文件系统
[root@localhost ~]# mkfs -t ext3 -c /dev/mailvg/mailvg01
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
362266624 inodes, 724507648 blocks
36225382 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
22111 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, 71663616, 78675968,
102400000, 214990848, 512000000, 550731776, 644972544
Checking for bad blocks (read-only test): done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 33 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
因为容量为2.7TB这个格式化过程会很慢，一直等到出现这些信才格式化完成
12、设置开机自动挂载
创建目录
[root@localhost /]# mkdir /data
然后编辑自动挂载文件
[root@localhost /]# vi /etc/fstab
LABEL=/ / ext3 defaults 1 1
LABEL=/var /var ext3 defaults 1 2
LABEL=/opt /opt ext3 defaults 1 2
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
LABEL=SWAP-sda5 swap swap defaults 0 0
/dev/mailvg/mailvg01 /data ext3 defaults 0 0
用VI编辑器 编辑/etc/fstab文件把下面的内容加到最后面，保存退出后重启系统。
/dev/mailvg/mailvg01 /data ext3 defaults 0 0
13、查看是否挂载成功
[root@localhost ~]# df -hv
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3 97G 4.4G 88G 5% /
/dev/sda6 35G 248M 33G 1% /var
/dev/sda2 97G 188M 92G 1% /opt
/dev/sda1 190M 12M 169M 7% /boot
tmpfs 16G 0 16G 0% /dev/shm
/dev/mapper/mailvg-mailvg01
2.7T 202M 2.6T 1% /data
最下面的就是 已挂载成功
14、常见 LVM 命令
功能
PV
VG
LV
搜索
pvscan
vgscan
lvscan
建立
pvcreate
vgcreate
lvcreate
列出
pvdisplay
vgdisplay
lvdisplay
增加
vgextend
lvextend
减少
vgreduce
lvreduce
删除
vgremove
lvremove
15、创建PV，扩容VG，LV
a、创建新的PV
pvcreate /dev/sdd
b、查看原VG
vgdisplay #查看当前已经存在的VG信息，以存在VG：vg为例
c、扩展原VG
vgextend vg /dev/sdd #扩展VolGroup00
d、查看原LV
lvdisplay #查看已经存在的LV信息，以存在LV：vg01为例
e、扩展原LV
[root@clent ~]# lvextend -L +10G /dev/vg/vg01
/dev/cdrom: open failed: 只读文件系统
Rounding up size to full physical extent 10 GB
Extending logical volume vg01 to 59.98 GB
Logical volume vg01 successfully resized
f、对扩展的LV执行该重设大小
[root@clent ~]# resize2fs /dev/vg/vg01 # 执行该重设大小，对于当前正在使用的vg01有效
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/vg/vg01 is mounted on /aaa; on-line resizing required
Performing an on-line resize of /dev/vg/vg01 to 15724544 (4k) blocks.
The filesystem on /dev/vg/vg01 is now 15724544 blocks long.
g、查看已经扩容LV所挂载的目录
df –h #查看挂载情况，已经扩容
原创文章请注明转载自技术小站本文地址：http://www.i5i6.net/post/6.html，标题：linux LVM管理
