Linux “/“ 分区扩容

巭犇

已于 2022-10-20 09:37:20 修改

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文章标签： centos

于 2022-03-23 14:58:47 首次发布

本文链接：https://blog.youkuaiyun.com/zyqash/article/details/123685343

版权

本文档详细介绍了在Linux系统中进行逻辑卷扩容的完整过程，包括查看当前分区大小、添加新磁盘、分区、安装软件包、创建物理卷、扩展卷组、扩展逻辑卷以及最后通过xfs_growfs使扩容生效。这一系列步骤帮助读者在遗忘操作细节时能迅速回忆并执行扩容任务。

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前言

扩容是一项很简单的工作，但是有时候因为长时间没有操作过扩容，指令会比较生疏，因此写一篇扩容的文档，方便在再次失忆的情况下能快速回忆起操作流程。

逻辑卷扩容的流程：创建PV-->扩容VG-->扩容LV。

以下是扩容的详细流程。

1、查看当前 / 分区大小

[root@rt7_node03 ~]# df -Th
Filesystem          Type      Size  Used Avail Use% Mounted on
/dev/mapper/cl-root xfs       7.1G  1.2G  6.0G  16% /
devtmpfs            devtmpfs  486M     0  486M   0% /dev
tmpfs               tmpfs     496M     0  496M   0% /dev/shm
tmpfs               tmpfs     496M  6.7M  490M   2% /run
tmpfs               tmpfs     496M     0  496M   0% /sys/fs/cgroup
/dev/vda1           xfs      1014M  139M  876M  14% /boot
tmpfs               tmpfs     100M     0  100M   0% /run/user/0

2、添加一块磁盘，查看新磁盘的大小

[root@rt7_node03 ~]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0          11:0    1 1024M  0 rom  
vda         252:0    0    9G  0 disk 
|-vda1      252:1    0    1G  0 part /boot
`-vda2      252:2    0    8G  0 part 
  |-cl-swap 253:0    0  924M  0 lvm  [SWAP]
  `-cl-root 253:1    0  7.1G  0 lvm  /
vdb         252:16   0   20G  0 disk

3、给新磁盘分区

[root@rt7_node03 ~]# fdisk /dev/vdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0x67c61676.

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): 
Using default response p
Partition number (1-4, default 1): 
First sector (2048-41943039, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): 
Using default value 41943039
Partition 1 of type Linux and of size 20 GiB is set

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
[root@rt7_node03 ~]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0          11:0    1 1024M  0 rom  
vda         252:0    0    9G  0 disk 
|-vda1      252:1    0    1G  0 part /boot
`-vda2      252:2    0    8G  0 part 
  |-cl-swap 253:0    0  924M  0 lvm  [SWAP]
  `-cl-root 253:1    0  7.1G  0 lvm  /
vdb         252:16   0   20G  0 disk 
`-vdb1      252:17   0   20G  0 part

4、安装所需的软件包

[root@rt7_node03 ~]# yum install -y lvm2-2.02.166-1.el7.x86_64

5、创建pv物理卷

[root@rt7_node03 ~]# pvcreate /dev/vdb1
  Physical volume "/dev/vdb1" successfully created.

6、查看新创建的物理卷

[root@rt7_node03 ~]# pvdisplay 
  --- Physical volume ---
  PV Name               /dev/vda2
  VG Name               cl
  PV Size               8.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              2047
  Free PE               0
  Allocated PE          2047
  PV UUID               KToRtg-Mwyz-bkxt-Erln-a5Ro-HJDw-orTvQo
   
  "/dev/vdb1" is a new physical volume of "20.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/vdb1
  VG Name               
  PV Size               20.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               po26cZ-PVjR-NZxG-UkDw-wzcC-yJ7z-EnXlGa

7、查看VG

[root@rt7_node03 ~]# vgdisplay 
  --- Volume group ---
  VG Name               cl
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               8.00 GiB
  PE Size               4.00 MiB
  Total PE              2047
  Alloc PE / Size       2047 / 8.00 GiB
  Free  PE / Size       0 / 0   
  VG UUID               U8mInR-Xnzq-hTka-AE2D-Y5fV-r3Qx-LLbdi9
   
[root@rt7_node03 ~]# vgs
  VG #PV #LV #SN Attr   VSize VFree
  cl   1   2   0 wz--n- 8.00g    0

8、扩展VG

[root@rt7_node03 ~]# vgextend cl /dev/vdb1
  Volume group "cl" successfully extended

9、查看VG

[root@rt7_node03 ~]# vgs
  VG #PV #LV #SN Attr   VSize  VFree 
  cl   2   2   0 wz--n- 27.99g 20.00g
[root@rt7_node03 ~]# vgdisplay 
  --- Volume group ---
  VG Name               cl
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  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               27.99 GiB
  PE Size               4.00 MiB
  Total PE              7166
  Alloc PE / Size       2047 / 8.00 GiB
  Free  PE / Size       5119 / 20.00 GiB
  VG UUID               U8mInR-Xnzq-hTka-AE2D-Y5fV-r3Qx-LLbdi9

10、查看LV

[root@rt7_node03 ~]# lvs
  LV   VG Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root cl -wi-ao----   7.09g                                                    
  swap cl -wi-ao---- 924.00m

11、扩展LV

[root@rt7_node03 ~]# lvextend -L +19G /dev/cl/root
  Size of logical volume cl/root changed from 7.09 GiB (1816 extents) to 26.09 GiB (6680 extents).
  Logical volume cl/root successfully resized.

12、使用xfs_growfs命令使扩容生效

[root@rt7_node03 ~]# xfs_growfs /dev/cl/root
meta-data=/dev/mapper/cl-root    isize=512    agcount=4, agsize=464896 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=1859584, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 1859584 to 6840320

如果逻辑卷是ext格式用resize2fs命令使扩容生效

13、查看 / 分区的大小

[root@rt7_node03 ~]# df -Th
Filesystem          Type      Size  Used Avail Use% Mounted on
/dev/mapper/cl-root xfs        27G  1.2G   25G   5% /
devtmpfs            devtmpfs  486M     0  486M   0% /dev
tmpfs               tmpfs     496M     0  496M   0% /dev/shm
tmpfs               tmpfs     496M  6.7M  490M   2% /run
tmpfs               tmpfs     496M     0  496M   0% /sys/fs/cgroup
/dev/vda1           xfs      1014M  139M  876M  14% /boot
tmpfs               tmpfs     100M     0  100M   0% /run/user/0

可以看到 / 分区已新增了19G。