Linux LVM文件系统管理的创建和扩展

LVM(Logical Volume Manager)逻辑卷管理是在Linux2.4内核以上实现的磁盘管理技术。LVM将一个或多个硬盘的分区在逻辑上集合，相当于一个大硬盘来使用，当硬盘的空间不够使用的时候，可以继续将其它的硬盘的分区加入其中，这样可以实现磁盘空间的动态管理，相对于普通的磁盘分区有很大的灵活性。与传统的磁盘与分区相比，LVM为计算机提供了更高层次的磁盘存储。它使系统管理员可以更方便的为应用与用户分配存储空间。在LVM管理下的存储卷可以按需要随时改变大小与移除(可能需对文件系统工具进行升级)。LVM也允许按用户组对存储卷进行管理，允许管理员用更直观的名称(如"data'、 'oracle')代替物理磁盘名(如'sda'、'sdb')来标识存储卷。

物理存储介质(The physical media)：这里指系统的存储设备/dev/sda1、/dev/xvdb1等，是存储系统最低层的存储单元。

物理卷(physical volume)：物理卷就是指硬盘分区或从逻辑上与磁盘分区具有同样功能的设备(如RAID)，是LVM的基本存储逻辑块，但和基本的物理存储介质(如分区、磁盘等)比较，却包含有与LVM相关的管理参数，PV即物理的磁盘分区。

卷组(Volume Group)：LVM卷组类似于非LVM系统中的物理硬盘，其由物理卷组成，可以在卷组上创建一个或多个“LVM分区”（逻辑卷），LVM卷组由一个或多个物理卷组成。

逻辑卷（logical volume）：LVM的逻辑卷类似于非LVM系统中的硬盘分区，在逻辑卷之上可以建立文件系统(比如/home或者/usr等)。

PE(physical extent)：每一个物理卷被划分为称为PE(Physical Extents)的基本单元，具有唯一编号的PE是可以被LVM寻址的最小单元。PE的大小是可配置的，默认为4MB。

LE(logical extent)：逻辑卷也被划分为被称为LE(Logical Extents) 的可被寻址的基本单位。在同一个卷组中，LE的大小和PE是相同的，并且一一对应。

创建PV

pvcreate /dev/xvdb1 /dev/xvdc1 /dev/xvde1

创建VG

vgcreate -s 8M datavg /dev/xvdb1 /dev/xvdc1 /dev/xvde1

创建LV

lvcreate -L 890G  -n lvdata  datavg

挂载LV

/dev/datavg/lvdata

创建PV

pvcreate /dev/xvdf1

扩展VG

vgextend datavg /dev/xvdf1

扩展LV

lvextend -L +100G /dev/datavg/lvdata

扩展文件系统

resize2fs /dev/datavg/lvdata

案例：

[root@hkpgsadg dev]# ls -l /dev/xvd*

brw-rw---- 1 root disk 202,  0 Apr 13 16:37 /dev/xvda

brw-rw---- 1 root disk 202,  1 Apr 13 16:36 /dev/xvda1

brw-rw---- 1 root disk 202,  2 Apr 13 16:36 /dev/xvda2

brw-rw---- 1 root disk 202,  3 Apr 13 16:36 /dev/xvda3

brw-rw---- 1 root disk 202, 16 Apr 13 16:39 /dev/xvdb

brw-rw---- 1 root disk 202, 17 Apr 13 16:39 /dev/xvdb1

brw-rw---- 1 root disk 202, 32 Apr 13 16:37 /dev/xvdc

brw-rw---- 1 root disk 202, 64 Apr 13 16:37 /dev/xvde

brw-rw---- 1 root disk 202, 80 Apr 13 16:37 /dev/xvdf

[root@hkpgsadg dev]# fdisk /dev/xvdc

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel

Building a new DOS disklabel with disk identifier 0x04acd4ca.

Changes will remain in memory only, until you decide to write them.

After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to

         switch off the mode (command 'c') and change display units to

         sectors (command 'u').

Command (m for help): n

Command action

   e   extended

   p   primary partition (1-4)

p

Partition number (1-4): 1

First cylinder (1-65270, default 1): 

Using default value 1

Last cylinder, +cylinders or +size{K,M,G} (1-65270, default 65270): 

Using default value 65270

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

[root@hkpgsadg dev]# ls -l /dev/xvd*

brw-rw---- 1 root disk 202,  0 Apr 13 16:37 /dev/xvda

brw-rw---- 1 root disk 202,  1 Apr 13 16:36 /dev/xvda1

brw-rw---- 1 root disk 202,  2 Apr 13 16:36 /dev/xvda2

brw-rw---- 1 root disk 202,  3 Apr 13 16:36 /dev/xvda3

brw-rw---- 1 root disk 202, 16 Apr 13 16:39 /dev/xvdb

brw-rw---- 1 root disk 202, 17 Apr 13 16:39 /dev/xvdb1

brw-rw---- 1 root disk 202, 32 Apr 13 16:39 /dev/xvdc

brw-rw---- 1 root disk 202, 33 Apr 13 16:39 /dev/xvdc1

brw-rw---- 1 root disk 202, 64 Apr 13 16:40 /dev/xvde

brw-rw---- 1 root disk 202, 65 Apr 13 16:40 /dev/xvde1

brw-rw---- 1 root disk 202, 80 Apr 13 16:40 /dev/xvdf

brw-rw---- 1 root disk 202, 81 Apr 13 16:40 /dev/xvdf1

[root@hkpgsadg dev]# pvcreate /dev/xvdb1 /dev/xvdc1 /dev/xvde1

  Physical volume "/dev/xvdb1" successfully created

  Physical volume "/dev/xvdc1" successfully created

  Physical volume "/dev/xvde1" successfully created

[root@hkpgsadg dev]# pvdisplay

  --- Physical volume ---

  PV Name               /dev/xvda2

  VG Name               VolGroup

  PV Size               19.51 GiB / not usable 3.00 MiB

  Allocatable           yes (but full)

  PE Size               4.00 MiB

  Total PE              4994

  Free PE               0

  Allocated PE          4994

  PV UUID               Tv6PfK-cNpj-zYU2-cPeY-Xp8H-guAW-YZOm7d

  --- Physical volume ---

  PV Name               /dev/xvda3

  VG Name               VolGroup

  PV Size               100.00 GiB / not usable 3.99 MiB

  Allocatable           yes (but full)

  PE Size               4.00 MiB

  Total PE              25599

  Free PE               0

  Allocated PE          25599

  PV UUID               hhOoov-6TnF-p1Mg-mPc6-66If-zNwT-v8cIKB

  "/dev/xvdb1" is a new physical volume of "100.00 GiB"

  --- NEW Physical volume ---

  PV Name               /dev/xvdb1

  VG Name               

  PV Size               100.00 GiB

  Allocatable           NO

  PE Size               0   

  Total PE              0

  Free PE               0

  Allocated PE          0

  PV UUID               OujuQi-rD1R-K91R-Ni82-jyAX-PpjD-ZnQvo5

  "/dev/xvdc1" is a new physical volume of "499.99 GiB"

  --- NEW Physical volume ---

  PV Name               /dev/xvdc1

  VG Name               

  PV Size               499.99 GiB

  Allocatable           NO

  PE Size               0   

  Total PE              0

  Free PE               0

  Allocated PE          0

  PV UUID               grJiiL-KGug-ef3c-XF2J-ffS1-AhTl-xfHSMW

  "/dev/xvde1" is a new physical volume of "300.00 GiB"

  --- NEW Physical volume ---

  PV Name               /dev/xvde1

  VG Name               

  PV Size               300.00 GiB

  Allocatable           NO

  PE Size               0   

  Total PE              0

  Free PE               0

  Allocated PE          0

  PV UUID               08dOWh-3dFQ-rQ00-VTGi-h9S2-PbaJ-aQKYSe

[root@hkpgsadg dev]# vgcreate -s 8M datavg /dev/xvdb1 /dev/xvdc1 /dev/xvde1

  Volume group "datavg" successfully created

[root@hkpgsadg dev]# vgdisplay

  --- Volume group ---

  VG Name               datavg

  System ID             

  Format                lvm2

  Metadata Areas        3

  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                3

  Act PV                3

  VG Size               899.98 GiB

  PE Size               8.00 MiB

  Total PE              115197

  Alloc PE / Size       0 / 0   

  Free  PE / Size       115197 / 899.98 GiB

  VG UUID               fINMY5-wBKS-QBKi-N6QI-ihMD-YaVb-j90u0x

  --- Volume group ---

  VG Name               VolGroup

  System ID             

  Format                lvm2

  Metadata Areas        2

  Metadata Sequence No  5

  VG Access             read/write

  VG Status             resizable

  MAX LV                0

  Cur LV                2

  Open LV               2

  Max PV                0

  Cur PV                2

  Act PV                2

  VG Size               119.50 GiB

  PE Size               4.00 MiB

  Total PE              30593

  Alloc PE / Size       30593 / 119.50 GiB

  Free  PE / Size       0 / 0   

  VG UUID               RdDeWr-qxlF-f1To-zNng-nxCV-e1Hd-3xVZfH

[root@hkpgsadg dev]# vgdisplay

  --- Volume group ---

  VG Name               datavg

  System ID             

  Format                lvm2

  Metadata Areas        3

  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                3

  Act PV                3

  VG Size               899.98 GiB

  PE Size               8.00 MiB

  Total PE              115197

  Alloc PE / Size       0 / 0   

  Free  PE / Size       115197 / 899.98 GiB

  VG UUID               fINMY5-wBKS-QBKi-N6QI-ihMD-YaVb-j90u0x

  --- Volume group ---

  VG Name               VolGroup

  System ID             

  Format                lvm2

  Metadata Areas        2

  Metadata Sequence No  5

  VG Access             read/write

  VG Status             resizable

  MAX LV                0

  Cur LV                2

  Open LV               2

  Max PV                0

  Cur PV                2

  Act PV                2

  VG Size               119.50 GiB

  PE Size               4.00 MiB

  Total PE              30593

  Alloc PE / Size       30593 / 119.50 GiB

  Free  PE / Size       0 / 0   

  VG UUID               RdDeWr-qxlF-f1To-zNng-nxCV-e1Hd-3xVZfH

[root@hkpgsadg dev]# vgdisplay datavg

  --- Volume group ---

  VG Name               datavg

  System ID             

  Format                lvm2

  Metadata Areas        3

  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                3

  Act PV                3

  VG Size               899.98 GiB

  PE Size               8.00 MiB

  Total PE              115197

  Alloc PE / Size       0 / 0   

  Free  PE / Size       115197 / 899.98 GiB

  VG UUID               fINMY5-wBKS-QBKi-N6QI-ihMD-YaVb-j90u0x

[root@hkpgsadg dev]# lvcreate -L 890G  -n lvdata  datavg

  Logical volume "lvdata" created

[root@hkpgsadg dev]# lvdisplay 

  --- Logical volume ---

  LV Path                /dev/datavg/lvdata

  LV Name                lvdata

  VG Name                datavg

  LV UUID                yFWfNu-E1cr-px49-K9tH-Q0vU-BjfL-yt8hWh

  LV Write Access        read/write

  LV Creation host, time hkpgsadg, 2016-04-13 16:45:21 +0800

  LV Status              available

  # open                 0

  LV Size                890.00 GiB

  Current LE             113920

  Segments               3

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:2

  --- Logical volume ---

  LV Path                /dev/VolGroup/lv_root

  LV Name                lv_root

  VG Name                VolGroup

  LV UUID                4bM3bz-gttp-qKgr-sd9L-d24M-RMEb-LO4L4h

  LV Write Access        read/write

  LV Creation host, time localhost.localdomain, 2014-07-07 18:28:07 +0800

  LV Status              available

  # open                 1

  LV Size                115.58 GiB

  Current LE             29589

  Segments               2

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:0

  --- Logical volume ---

  LV Path                /dev/VolGroup/lv_swap

  LV Name                lv_swap

  VG Name                VolGroup

  LV UUID                Ic6bZU-mt6c-b0LK-1n7F-62Kc-16V1-TkcXBU

  LV Write Access        read/write

  LV Creation host, time localhost.localdomain, 2014-07-07 18:28:11 +0800

  LV Status              available

  # open                 1

  LV Size                3.92 GiB

  Current LE             1004

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:1

[root@hkpgsadg dev]# mkfs.ext4 /dev/datavg/lvdata

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

58327040 inodes, 233308160 blocks

11665408 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4294967296

7120 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, 71663616, 78675968, 

        102400000, 214990848

Writing inode tables: done                            

Creating journal (32768 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 32 mounts or

180 days, whichever comes first.  Use tune2fs -c or -i to override.

[root@hkpgsadg dev]# mkdir /data

[root@hkpgsadg dev]# mount /dev/datavg/lvdata /data 

[root@hkpgsadg dev]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup-lv_root

                      114G  4.5G  104G   5% /

tmpfs                  62G     0   62G   0% /dev/shm

/dev/xvda1            485M   32M  428M   7% /boot

/dev/mapper/datavg-lvdata

                      877G  200M  832G   1% /data

[root@hkpgsadg dev]# 

[root@hkpgsadg data]# pvcreate /dev/xvdf1

  Physical volume "/dev/xvdf1" successfully created

[root@hkpgsadg data]# vgextend datavg /dev/xvdf1

  Volume group "datavg" successfully extended

[root@hkpgsadg data]# lvdisplay

  --- Logical volume ---

  LV Path                /dev/datavg/lvdata

  LV Name                lvdata

  VG Name                datavg

  LV UUID                yFWfNu-E1cr-px49-K9tH-Q0vU-BjfL-yt8hWh

  LV Write Access        read/write

  LV Creation host, time hkpgsadg, 2016-04-13 16:45:21 +0800

  LV Status              available

  # open                 1

  LV Size                890.00 GiB

  Current LE             113920

  Segments               3

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:2

[root@hkpgsadg data]# vgdisplay

  --- Volume group ---

  VG Name               datavg

  System ID             

  Format                lvm2

  Metadata Areas        4

  Metadata Sequence No  3

  VG Access             read/write

  VG Status             resizable

  MAX LV                0

  Cur LV                1

  Open LV               1

  Max PV                0

  Cur PV                4

  Act PV                4

  VG Size               1.17 TiB

  PE Size               8.00 MiB

  Total PE              153596

  Alloc PE / Size       113920 / 890.00 GiB

  Free  PE / Size       39676 / 309.97 GiB

  VG UUID               fINMY5-wBKS-QBKi-N6QI-ihMD-YaVb-j90u0x

[root@hkpgsadg data]# lvextend -L +100G /dev/datavg/lvdata

  Extending logical volume lvdata to 990.00 GiB

  Logical volume lvdata successfully resized

[root@hkpgsadg data]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup-lv_root

                      114G  4.5G  104G   5% /

tmpfs                  62G     0   62G   0% /dev/shm

/dev/xvda1            485M   32M  428M   7% /boot

/dev/mapper/datavg-lvdata

                      877G  200M  832G   1% /data

[root@hkpgsadg data]# resize2fs /dev/datavg/lvdata

resize2fs 1.41.12 (17-May-2010)

Filesystem at /dev/datavg/lvdata is mounted on /data; on-line resizing required

old desc_blocks = 56, new_desc_blocks = 62

Performing an on-line resize of /dev/datavg/lvdata to 259522560 (4k) blocks.

The filesystem on /dev/datavg/lvdata is now 259522560 blocks long.

[root@hkpgsadg data]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup-lv_root

                      114G  4.5G  104G   5% /

tmpfs                  62G     0   62G   0% /dev/shm

/dev/xvda1            485M   32M  428M   7% /boot

/dev/mapper/datavg-lvdata

                      975G  200M  925G   1% /data

Created by Tony.Tang[TangYun]2016.04

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