基于Linux的LVM无缝磁盘水平扩容

栏目: 后端 · 发布时间: 5年前

内容简介：这时候，我们假设服务器已经有如下东西：首先查看软件是否安装：软件准备好后顺便查看下 VM 硬件:

名称	属性
CPU	x5650
内存	4G
磁盘	20G+4TB

基于 <a href='https://www.codercto.com/topics/18170.html'>Linux</a> 的LVM无缝磁盘水平扩容

这时候，我们假设服务器已经有如下东西：

安装好了Parted（yum install parted）
分区容量已经告捷，公司为服务器增加了一块4T硬盘用来增加容量！
除了/boot分区外，其余都为LVM 模式的扩展逻辑分区

软件安装与信息查看

首先查看软件是否安装：

[root@Candy ~]# rpm -qa | grep lvm
lvm2-libs-2.02.118-2.el6.x86_64
lvm2-2.02.118-2.el6.x86_64
[root@Candy ~]# lv
lvchange     lvextend     lvmdiskscan  lvmsar       lvresize
lvconvert    lvm          lvmdump      lvreduce     lvs
lvcreate     lvmchange    lvmetad      lvremove     lvscan
lvdisplay    lvmconf      lvmsadc      lvrename
[root@Candy ~]# rpm -qa | grep parted
parted-2.1-29.el6.x86_64
复制代码

软件准备好后顺便查看下 VM 硬件:

[root@Candy ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_candy-root
                      7.3G  231M  6.7G   4% /
tmpfs                 1.9G     0  1.9G   0% /dev/shm
/dev/sda1             477M   30M  422M   7% /boot
/dev/mapper/vg_candy-home
                      3.9G  8.0M  3.7G   1% /home
/dev/mapper/vg_candy-usr
                      3.9G  382M  3.3G  11% /usr
/dev/mapper/vg_candy-var
                      3.9G   63M  3.6G   2% /var
[root@Candy ~]# fdisk -l
Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 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: 0x0006e71c
   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        2611    20458496   8e  Linux LVM
Disk /dev/sdb: 4398.0 GB, 4398046511104 bytes
255 heads, 63 sectors/track, 534698 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_candy-root: 8061 MB, 8061452288 bytes
255 heads, 63 sectors/track, 980 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_candy-usr: 4294 MB, 4294967296 bytes
255 heads, 63 sectors/track, 522 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_candy-var: 4294 MB, 4294967296 bytes
255 heads, 63 sectors/track, 522 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_candy-home: 4294 MB, 4294967296 bytes
255 heads, 63 sectors/track, 522 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@Candy ~]# ls /dev/sd*
/dev/sda  /dev/sda1  /dev/sda2  /dev/sdb
复制代码

这时候我们看到，Centos 已经知道有个sdb的盘了，但是没挂载与分区。

使用Parted进行扩容前的分区

现在假设除了/boot 其余分区都满了! 我们需要先进行分区，将4T的硬盘用上(/dev/sdb).

[root@Candy ~]# parted /dev/sdb
GNU Parted 2.1
使用 /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel
新的磁盘标签类型？ gpt
(parted) mkpart
分区名称？  []?
文件系统类型？  [ext2]? ext4
起始点？ 0T
结束点？ 4T
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 4398GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number  Start   End     Size    File system  Name  标志
 1      1049kB  4398GB  4398GB
(parted)set 1 lvm on
(parted)p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 4398GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number  Start   End     Size    File system  Name  标志
1      1049kB  4398GB  4398GB                      lvm
(parted)q
[root@Candy ~]# ls /dev/sd*
/dev/sda  /dev/sda1  /dev/sda2  /dev/sdb  /dev/sdb1
复制代码

现在让我们来解释一下操作：

mklabel将磁盘转换为gpt分区，因为MBR分区无法支持TB级硬盘（具体请自行查阅，parted当然也支持TB级以下的操作）
mkpart将转换好的gpt磁盘进行分区，需要提供文件系统类型、开始点、结束点。
输入p 打印出刚才才做后生成的分区。
set 1 lvm on 是将num为1的分区，tager设置为LVM ，这样才能添加到vm卷组里

下一步，我们查看我们的LVM组名叫什么:

[root@Candy ~]# vgs
  VG       #PV #LV #SN Attr   VSize  VFree
  vg_candy   1   4   0 wz--n- 19.51g    0
  
[root@Candy ~]# vgdisplay
  --- Volume group ---
  VG Name               vg_candy
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  5
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                4
  Open LV               4
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               19.51 GiB
  PE Size               4.00 MiB
  Total PE              4994
  Alloc PE / Size       4994 / 19.51 GiB
  Free  PE / Size       0 / 0
  VG UUID               Gcm5Ml-fc88-Xk5q-xuPC-Kj7Y-alfK-i770Gc
[root@Candy ~]# lvscan
  ACTIVE            '/dev/vg_candy/usr' [4.00 GiB] inherit
  ACTIVE            '/dev/vg_candy/var' [4.00 GiB] inherit
  ACTIVE            '/dev/vg_candy/home' [4.00 GiB] inherit
  ACTIVE            '/dev/vg_candy/root' [7.51 GiB] inherit
[root@Candy ~]#
复制代码

知道lvm卷组叫 'vg_candy'了, 我们就使用vgextend来向lvm 'vg_candy' 卷组添加成员了.

[root@Candy ~]# vgextend vag_candy /dev/sdb1
Physical volume "/dev/sdb1" successfully created
Volume group "vg_candy" successfully extended
复制代码

现在我们再用vgs命令看一下pv个数:

[root@Candy ~]# vgs
VG       #PV #LV #SN Attr   VSize VFree
vg_candy   2   4   0 wz--n- 4.02t 4.00t
复制代码

大家对比未添加时的vgs是否有看到PV个数从1变为2了！

现在让我们用vgdisplay看看现在分区的容量.

[root@Candy ~]# vgdisplay
  --- Volume group ---
  VG Name               vg_candy
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                4
  Open LV               4
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               4.02 TiB
  PE Size               4.00 MiB
  Total PE              1053569
  Alloc PE / Size       4994 / 19.51 GiB
  Free  PE / Size       1048575 / 4.00 TiB
  VG UUID               Gcm5Ml-fc88-Xk5q-xuPC-Kj7Y-alfK-i770Gc
复制代码

再次对比未添加的vgdiplay命令发现，FreePE 的value 从 0 / 0 变为 1048575 / 4.00 TiB . 这样说明Candy已经成功将4TB的lvm 分区添加进入到vg_candy 逻辑卷组里了。

现在我们对所有逻辑分区进行扩容前，df -h 看看有哪些分区。

[root@Candy ~]# df -h
Filesystem                 Size  Used Avail Use% Mounted on
/dev/mapper/vg_candy-root  7.3G  231M  6.7G   4%  /
 tmpfs                     1.9G     0  1.9G   0%  /dev/shm
/dev/sda1                  477M   30M  422M   7%  /boot
/dev/mapper/vg_candy-home  3.9G  8.0M  3.7G   1%  /home                 
/dev/mapper/vg_candy-usr   3.9G  382M  3.3G  11%  /usr
/dev/mapper/vg_candy-var   3.9G   63M  3.6G   2%  /var
复制代码

现在麻烦的事已经做完了，接下来就剩下为分区进行扩容了.

为磁盘进行扩容

假设：我们需要向这些分区都添加500G容量: / 、 /home 、 /usr 、 /var

[root@Candy ~]# lvextend -L +500G /dev/mapper/vg_candy-root
  Size of logical volume vg_candy/root changed from 7.51 GiB (1922 extents) to 507.51 GiB (129922 extents).
  Logical volume root successfully resized
  
[root@Candy ~]# lvextend -L +500G /dev/mapper/vg_candy-home
  Size of logical volume vg_candy/home changed from 4.00 GiB (1024 extents) to 504.00 GiB (129024 extents).
  Logical volume home successfully resized
  
[root@Candy ~]# lvextend -L +500G /dev/mapper/vg_candy-usr
  Size of logical volume vg_candy/usr changed from 4.00 GiB (1024 extents) to 504.00 GiB (129024 extents).
  Logical volume usr successfully resized
  
[root@Candy ~]# lvextend -L +500G /dev/mapper/vg_candy-var
  Size of logical volume vg_candy/var changed from 4.00 GiB (1024 extents) to 504.00 GiB (129024 extents).
  Logical volume var successfully resized
复制代码

大家注意，这一步操作时不可逆的！如果输入了错误的分区名字还好！如果添加到其它分区了，就得重复N遍来缩容，比较麻烦哦！建议大家注仔细核对上面的FileSystem. 切记切记....

提示扩容成功！让我们再次用上述命令查看LVM信息:

[root@Candy ~]# vgs
  VG       #PV #LV #SN Attr   VSize VFree
  vg_candy   2   4   0 wz--n- 4.02t 2.05t 
  
[root@Candy ~]# lvscan
  ACTIVE            '/dev/vg_candy/usr' [504.00 GiB] inherit
  ACTIVE            '/dev/vg_candy/var' [504.00 GiB] inherit
  ACTIVE            '/dev/vg_candy/home' [504.00 GiB] inherit
  ACTIVE            '/dev/vg_candy/root' [507.51 GiB] inherit
  
[root@Candy ~]# vgdisplay
  --- Volume group ---
  VG Name               vg_candy
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  10
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                4
  Open LV               4
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               4.02 TiB
  PE Size               4.00 MiB
  Total PE              1053569
  Alloc PE / Size       516994 / 1.97 TiB
  Free  PE / Size       536575 / 2.05 TiB
  VG UUID               Gcm5Ml-fc88-Xk5q-xuPC-Kj7Y-alfK-i770Gc
  
[root@Candy ~]# df -h
Filesystem                 Size  Used Avail Use% Mounted on
/dev/mapper/vg_candy-root  7.3G  231M  6.7G   4%  /
 tmpfs                     1.9G     0  1.9G   0%  /dev/shm
/dev/sda1                  477M   30M  422M   7%  /boot
/dev/mapper/vg_candy-home  3.9G  8.0M  3.7G   1%  /home                 
/dev/mapper/vg_candy-usr   3.9G  382M  3.3G  11%  /usr
/dev/mapper/vg_candy-var   3.9G   63M  3.6G   2%  /var
复制代码

看到这里大家可能奇怪！为什么df -h 还没变呢?

刷新磁盘信息与写入

我们需要用resize2fs 重设分区大小, 这样才能使df -h 也能生效.

而resize2fs 需要的时间与你给予的容量线性叠加. 也就是说你给的容量越多，resize2fs 的需要的时间就越多。

[root@Candy ~]# resize2fs /dev//mapper/vg_candy-root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev//mapper/vg_candy-root is mounted on /; on-line resizing required old desc_blocks = 1, new_desc_blocks = 32
Performing an on-line resize of /dev//mapper/vg_candy-root to 133040128 (4k) blocks.
The filesystem on /dev//mapper/vg_candy-root is now 133040128 blocks long.

[root@Candy ~]# resize2fs /dev//mapper/vg_candy-usr
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev//mapper/vg_candy-usr is mounted on /usr; on-line resizing required old desc_blocks = 1, new_desc_blocks = 32
Performing an on-line resize of /dev//mapper/vg_candy-usr to 132120576 (4k) blocks.
The filesystem on /dev//mapper/vg_candy-usr is now 132120576 blocks long.

[root@Candy ~]# resize2fs /dev//mapper/vg_candy-var
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev//mapper/vg_candy-var is mounted on /var; on-line resizing required old desc_blocks = 1, new_desc_blocks = 32
Performing an on-line resize of /dev//mapper/vg_candy-var to 132120576 (4k) blocks.
The filesystem on /dev//mapper/vg_candy-var is now 132120576 blocks long.

[root@Candy ~]# resize2fs /dev//mapper/vg_candy-home
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev//mapper/vg_candy-home is mounted on /home; on-line resizing required old desc_blocks = 1, new_desc_blocks = 32
Performing an on-line resize of /dev//mapper/vg_candy-home to 132120576 (4k) blocks.
The filesystem on /dev//mapper/vg_candy-home is now 132120576 blocks long.

[root@Candy ~]# df -h
Filesystem                    Size  Used Avail Use%  Mounted on
/dev/mapper/vg_candy-root     500G  245M  474G   1%  /
tmpfs                         1.9G     0  1.9G   0%  /dev/shm
/dev/sda1                     477M   30M  422M   7%  /boot
/dev/mapper/vg_candy-home     496G   16M  471G   1%  /home
/dev/mapper/vg_candy-usr      496G  390M  471G   1%  /usr
/dev/mapper/vg_candy-var      496G   71M  471G   1%  /var
复制代码

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持码农网

查看所有标签

猜你喜欢:

本站部分资源来源于网络，本站转载出于传递更多信息之目的，版权归原作者或者来源机构所有，如转载稿涉及版权问题，请联系我们。

码农书籍

ActionScript 3.0 Cookbook

Joey Lott、Darron Schall、Keith Peters / Adobe Dev Library / 2006-10-11 / GBP 28.50

Well before Ajax and Microsoft's Windows Presentation Foundation hit the scene, Macromedia offered the first method for building web pages with the responsiveness and functionality of desktop programs......一起来看看《ActionScript 3.0 Cookbook》这本书的介绍吧!

码农工具

MD5 加密

MD5 加密工具

RGB HSV 转换

RGB HSV 互转工具

HEX CMYK 转换工具

HEX CMYK 互转工具