DDR爱好者之家 Design By 杰米

环境

名称 属性 CPU x5650 内存 4G 磁盘 20G+4TB

详解基于Linux的LVM无缝磁盘水平扩容 

详解基于Linux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

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

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? []"htmlcode">
[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 ~]#

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

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

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

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

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

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

看到这里大家可能奇怪! 为什么df -h 还没变呢"htmlcode">

[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

结束语

顺便给大家晒一张重启后系统自动挂载的图!

详解基于Linux的LVM无缝磁盘水平扩容

详解基于Linux的LVM无缝磁盘水平扩容

Linux系统还是比较聪明的. 其实重启与不重启都能使用, 只是为大家演示重启后的效果.

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。

DDR爱好者之家 Design By 杰米
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
DDR爱好者之家 Design By 杰米