基於Linux的LVM無縫磁盤水平擴容

時間  2019-11-06
標籤 基於 linux lvm 無縫 磁盤 水平 擴容 欄目 Linux 简体版
原文   原文鏈接

環境

名稱 屬性
CPU x5650
內存 4G
磁盤 20G+4TB

這時候，咱們假設服務器已經有以下東西：bash

  • 安裝好了Parted（yum install parted）服務器

  • 分區容量已經告捷，公司爲服務器增長了一塊4T硬盤用來增長容量！app

  • 除了/boot分區外，其他都爲LVM 模式的擴展邏輯分區ide

軟件安裝與信息查看

首先查看軟件是否安裝：ui

[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
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軟件準備好後順便查看下 VM 硬件:spa

[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
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這時候咱們看到，Centos 已經知道有個sdb的盤了，可是沒掛載與分區。code

使用Parted進行擴容前的分區

如今假設除了/boot 其他分區都滿了! 咱們須要先進行分區，將4T的硬盤用上(/dev/sdb).orm

[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
新的磁盤標籤類型？ gpt
(parted) mkpart
分區名稱？  []?
文件系統類型？  [ext2]? ext4
起始點？ 0T
結束點？ 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  標誌
 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  標誌
1      1049kB  4398GB  4398GB                      lvm
(parted)q
[root@Candy ~]# ls /dev/sd*
/dev/sda  /dev/sda1  /dev/sda2  /dev/sdb  /dev/sdb1
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如今讓咱們來解釋一下操做：cdn

  1. mklabel將磁盤轉換爲gpt分區，由於MBR分區沒法支持TB級硬盤（具體請自行查閱，parted固然也支持TB級如下的操做）blog

  2. mkpart將轉換好的gpt磁盤進行分區，須要提供文件系統類型、開始點、結束點。

  3. 輸入p 打印出剛纔才作後生成的分區。

  4. set 1 lvm on 是將num爲1的分區，tager設置爲LVM ，這樣才能添加到vm卷組裏

下一步，咱們查看咱們的LVM組名叫什麼:

[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 ~]#
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知道lvm卷組叫 'vg_candy'了, 咱們就使用vgextend來向lvm 'vg_candy' 卷組添加成員了.

[root@Candy ~]# vgextend vag_candy /dev/sdb1
Physical volume "/dev/sdb1" successfully created
Volume group "vg_candy" successfully extended
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如今咱們再用vgs命令看一下pv個數:

[root@Candy ~]# vgs
VG       #PV #LV #SN Attr VSize VFree
vg_candy   2   4   0 wz--n- 4.02t 4.00t
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你們對比未添加時的vgs是否有看到PV個數從1變爲2了！

如今讓咱們用vgdisplay看看如今分區的容量.

[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
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再次對比未添加的vgdiplay命令發現，FreePE 的value 從 0 / 0 變爲 1048575 / 4.00 TiB . 這樣說明Candy已經成功將4TB的lvm 分區添加進入到vg_candy 邏輯卷組裏了。

如今咱們對全部邏輯分區進行擴容前，df -h 看看有哪些分區。

[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
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如今麻煩的事已經作完了，接下來就剩下爲分區進行擴容了.

爲磁盤進行擴容

假設：咱們須要向 這些分區都添加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
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你們注意，這一步操做時不可逆的！ 若是輸入了錯誤的分區名字還好！ 若是添加到其它分區了，就得重複N遍來縮容，比較麻煩哦！ 建議你們注仔細覈對上面的FileSystem. 切記切記....

提示擴容成功！ 讓咱們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
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看到這裏你們可能奇怪！ 爲何df -h 還沒變呢?

刷新磁盤信息與寫入

咱們須要用resize2fs 重設分區大小, 這樣才能使df -h 也能生效.

而resize2fs 須要的時間與你給予的容量線性疊加. 也就是說你給的容量越多，resize2fs 的須要的時間就越多。

[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
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結束語

順便給你們曬一張重啓後系統自動掛載的圖！

Linux系統仍是比較聰明的. 其實重啓與不重啓都能使用, 只是爲你們演示重啓後的效果.

但願此文章能幫助你們平滑的進行水平擴容！

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