LINUX系统中的PV LV VG的关系及管理

操作系统基于Centos 6.5

Linux  *****   2.6.32-431.el6.x86_64 #1 SMP Fri Nov 22 03:15:09 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

一.

PV(physical volume)即物理卷,就是物理磁盘,可以通过fdisk -l 查看操作系统有几块硬盘

VG(volume group)即卷组,就是一组物理磁盘的组合,里面可以有一块硬盘也可以有多块硬盘

LV(logical volume)及逻辑卷,就是在VG(指定的物理磁盘组)里面划分出来的

可以说成是PV就是硬盘,而VG就是管理硬盘的操作系统,而LV就是操作系统分出来的各个分区.

PV->VG->LV->  文件系统使用(挂载到某个目录)

 

二.命令集合

1.PV

pvcreate :根据物理盘,创建pv

pvscan :查询目前系统里的pv

pvdisplay:显示pv的状态

pvremove:将pv属性移除

 

2.VG

vgcreate:创建vg

vgscan:查找当前系统里面的vg

vgdisplay:显示当前系统vg的状态

vgextend:给vg添加额外的pv

vgreduce:在vg内删除pv

vgchange:设置vg是否是启动状态(active)

vgremove:删除一个vg

 

3.LV

 

lvcreate:创建lv

lvscan:查询当前系统的lv

lvdisplay:显示lv的属性

lvextend:给lv添加容量

lvredurce:给lv减少容量

lvremove:删除一个lv

lvresize:对lv大小的容量进行调整

 

 

三.实际操作

下面实际操作下,来看看

1.从下看到只是把sda这块硬盘用了,做了vg(vg_dsgdata),并且在vg(vg_dsgdata)下建了/dev/vg_dsgdata/lv_root, /dev/vg_dsgdata/lv_swap, /dev/vg_dsgdata/lv_home三个lv, 通过df -h看到/dev/mapper/vg_dsgdata-lv_root挂载在根目录/下,/dev/mapper/vg_dsgdata-lv_home挂载在/home目录下.从上述看,还剩余sdb,sdc,sdd三块硬盘没有使用

[root@dsgdata ~]# fdisk -l

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdd: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a2d9e

Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              64      121602   976248832   8e  Linux LVM

Disk /dev/mapper/vg_dsgdata-lv_root: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/vg_dsgdata-lv_swap: 8355 MB, 8355053568 bytes
255 heads, 63 sectors/track, 1015 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/vg_dsgdata-lv_home: 937.6 GB, 937632464896 bytes
255 heads, 63 sectors/track, 113993 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

[root@dsgdata ~]#

[root@dsgdata ~]# pvdisplay
--- Physical volume ---
PV Name               /dev/sda2
VG Name               vg_dsgdata
PV Size               931.02 GiB / not usable 4.00 MiB
Allocatable           yes (but full)
PE Size               4.00 MiB
Total PE              238341
Free PE               0
Allocated PE          238341
PV UUID               lPOKfO-HZ6y-4ubK-5TPk-FuB0-ypCU-y0mK1R

[root@dsgdata ~]#

[root@dsgdata ~]# vgdisplay
--- Volume group ---
VG Name               vg_dsgdata
System ID
Format                lvm2
Metadata Areas        1
Metadata Sequence No  4
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               931.02 GiB
PE Size               4.00 MiB
Total PE              238341
Alloc PE / Size       238341 / 931.02 GiB
Free  PE / Size       0 / 0
VG UUID               zQcZh0-2t6e-9LuM-zHnv-R0tG-sQDi-Ba3wLK

[root@dsgdata ~]# lvdisplay
--- Logical volume ---
LV Path                /dev/vg_dsgdata/lv_root
LV Name                lv_root
VG Name                vg_dsgdata
LV UUID                D7Z7jC-v0aK-fYJ5-AbcN-LmjX-nMEJ-dwpcm0
LV Write Access        read/write
LV Creation host, time dsgdata, 2014-03-05 17:59:43 +0800
LV Status              available
# open                 1
LV Size                50.00 GiB
Current LE             12800
Segments               1
Allocation             inherit
Read ahead sectors     auto
- currently set to     256
Block device           253:0

--- Logical volume ---
LV Path                /dev/vg_dsgdata/lv_swap
LV Name                lv_swap
VG Name                vg_dsgdata
LV UUID                0HrVlq-IS9g-hNH0-R1Sr-hvcd-BUI2-hkjfLh
LV Write Access        read/write
LV Creation host, time dsgdata, 2014-03-05 18:00:00 +0800
LV Status              available
# open                 1
LV Size                7.78 GiB
Current LE             1992
Segments               1
Allocation             inherit
Read ahead sectors     auto
- currently set to     256
Block device           253:1

--- Logical volume ---
LV Path                /dev/vg_dsgdata/lv_home
LV Name                lv_home
VG Name                vg_dsgdata
LV UUID                PC4IMN-Nvm3-UpaB-Em5I-NCvq-fzPF-MKcqOs
LV Write Access        read/write
LV Creation host, time dsgdata, 2014-03-05 18:00:01 +0800
LV Status              available
# open                 1
LV Size                873.24 GiB
Current LE             223549
Segments               1
Allocation             inherit
Read ahead sectors     auto
- currently set to     256
Block device           253:2

[root@dsgdata ~]#

[root@dsgdata ~]# df -h
Filesystem                      Size  Used Avail Use% Mounted on
/dev/mapper/vg_dsgdata-lv_root   50G  4.4G   43G  10% /
tmpfs                           3.9G  228K  3.9G   1% /dev/shm
/dev/sda1                       485M   40M  420M   9% /boot
/dev/mapper/vg_dsgdata-lv_home  860G  200M  816G   1% /home
[root@dsgdata ~]#

2.下面手工操作,创建增加减少删除关于pv,vg,lv的操作

创建pv

[root@dsgdata /]# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created
[root@dsgdata /]# pvdisplay
--- Physical volume ---
PV Name               /dev/sda2
VG Name               vg_dsgdata
PV Size               931.02 GiB / not usable 4.00 MiB
Allocatable           yes (but full)
PE Size               4.00 MiB
Total PE              238341
Free PE               0
Allocated PE          238341
PV UUID               lPOKfO-HZ6y-4ubK-5TPk-FuB0-ypCU-y0mK1R

"/dev/sdb" is a new physical volume of "931.51 GiB"
--- NEW Physical volume ---
PV Name               /dev/sdb
VG Name
PV Size               931.51 GiB
Allocatable           NO
PE Size               0
Total PE              0
Free PE               0
Allocated PE          0
PV UUID               MO29Sj-3lEd-Licp-BNxD-9qPH-v5y4-zLUNHI

[root@dsgdata /]# pvscan
PV /dev/sda2   VG vg_dsgdata      lvm2 [931.02 GiB / 0    free]
PV /dev/sdb                       lvm2 [931.51 GiB]
Total: 2 [1.82 TiB] / in use: 1 [931.02 GiB] / in no VG: 1 [931.51 GiB]
[root@dsgdata /]#

[root@dsgdata /]# pvremove /dev/sdb
  Labels on physical volume "/dev/sdb" successfully wiped
[root@dsgdata /]# pvscan
  PV /dev/sda2   VG vg_dsgdata   lvm2 [931.02 GiB / 0    free]
  Total: 1 [931.02 GiB] / in use: 1 [931.02 GiB] / in no VG: 0 [0   ]<pre code_snippet_id="220533" snippet_file_name="blog_20140306_6_5401133" class="html" name="code">[root@dsgdata /]# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created

 

3.创建VG

[root@dsgdata /]# vgcreate DATA /dev/sdb  

Volume group "DATA" successfully created

[root@dsgdata /]#

[root@dsgdata /]# vgdisplay DATA  

--- Volume group ---  VG Name               DATA  System ID               Format                lvm2  Metadata Areas        1  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                1  Act PV                1  VG Size   
d99a
            931.51 GiB  PE Size               4.00 MiB  Total PE              238467  Alloc PE / Size       0 / 0     Free  PE / Size       238467
/ 931.51 GiB  VG UUID               HhP6O7-sjLT-xzA7-YqLl-QsOJ-lQSM-3sN5VS   

[root@dsgdata /]#

给VG添加或者减少容量：

[root@dsgdata /]# pvcreate /dev/sdc  Physical volume "/dev/sdc" 

successfully created

[root@dsgdata /]# vgextend DATA /dev/sdc  

Volume group "DATA" successfully extended

[root@dsgdata /]# vgdisplay DATA  

--- Volume group ---  VG Name               DATA  System ID               Format                lvm2  Metadata Areas        2  Metadata Sequence No  2  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               1.82 TiB  PE Size               4.00 MiB  Total PE              476934  Alloc PE / Size       0 / 0     Free  PE / Size       476934
/ 1.82 TiB  VG UUID               HhP6O7-sjLT-xzA7-YqLl-QsOJ-lQSM-3sN5VS  

[root@dsgdata /]# vgreduce DATA /dev/sdc  

Removed "/dev/sdc" from volume group "DATA"

[root@dsgdata /]# vgdisplay DATA  

--- Volume group ---  VG Name               DATA  System ID               Format                lvm2  Metadata Areas        1  Metadata Sequence No  3  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV               
0  Open LV               0  Max PV                0  Cur PV                1  Act PV                1  VG Size               931.51 GiB  PE Size               4.00 MiB  Total PE              238467  Alloc PE / Size       0 / 0     Free  PE / Size       238467
/ 931.51 GiB  VG UUID               HhP6O7-sjLT-xzA7-YqLl-QsOJ-lQSM-3sN5VS   

[root@dsgdata /]#

 

4.创建LV,并挂载

 

[root@dsgdata /]# lvscan  

ACTIVE            '/dev/vg_dsgdata/lv_root' [50.00 GiB] inherit  

ACTIVE            '/dev/vg_dsgdata/lv_swap' [7.78 GiB] inherit  

ACTIVE            '/dev/vg_dsgdata/lv_home' [873.24 GiB] inherit

[root@dsgdata /]# lvcreate -n test -L 100G DATA  

Logical volume "test" created

[root@dsgdata /]# lvscan  ACTIVE            

'/dev/DATA/test' [100.00 GiB] inherit  ACTIVE           

'/dev/vg_dsgdata/lv_root' [50.00 GiB] inherit  ACTIVE           

'/dev/vg_dsgdata/lv_swap' [7.78 GiB] inherit  ACTIVE            

'/dev/vg_dsgdata/lv_home' [873.24 GiB] inherit

[root@dsgdata /]#

在根目录下创建目录CXF

[root@dsgdata /]# mkdir /cxf

对逻辑卷进行格式化：

<p>[root@dsgdata /]# mkfs -t ext4 /dev/DATA/test
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
6553600 inodes, 26214400 blocks
1310720 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
800 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872</p><p>Writing inode tables: done                           
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information:
done</p><p>This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
[root@dsgdata /]# </p>

将逻辑卷/dev/DATA/test挂载到/cxf目录下:

[root@dsgdata /]# mount /dev/DATA/test /cxf
[root@dsgdata /]# df -h
Filesystem                      Size  Used Avail Use% Mounted on
/dev/mapper/vg_dsgdata-lv_root   50G  4.4G   43G  10% /
tmpfs                           3.9G  228K  3.9G   1% /dev/shm
/dev/sda1                       485M   40M  420M   9% /boot
/dev/mapper/vg_dsgdata-lv_home  860G  200M  816G   1% /home
/dev/mapper/DATA-test            99G  188M   94G   1% /cxf
[root@dsgdata /]#