CentOS7 基于lvm扩容根目录

本文主要是介绍CentOS7 基于lvm扩容根目录，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

Linux操作系统安装好之后，可以通过 df -h 命令查看磁盘挂载信息和空间使用率

[root@localhost ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
devtmpfs                 7.8G     0  7.8G   0% /dev
tmpfs                    7.8G   60K  7.8G   1% /dev/shm
tmpfs                    7.8G  9.0M  7.8G   1% /run
tmpfs                    7.8G     0  7.8G   0% /sys/fs/cgroup
/dev/mapper/centos-root   46G  6.6G   40G  15% /
/dev/sda1                197M  166M   32M  84% /boot
tmpfs                    1.6G     0  1.6G   0% /run/user/1000
tmpfs                    1.6G     0  1.6G   0% /run/user/0

如上所示，磁盘根目录只有不到50G，根据实际业务需要将磁盘空间扩容到200G，如果是物理机只能增加磁盘，如果是虚拟机则可以直接扩容。

具体操作步骤如下

1.分区 fdisk命令

[root@localhost ~]# fdisk /dev/sda 
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.


Command (m for help): n #创建一个新分区

分区创建后需要将新的分区信息刷新到内核中，可执行两次，确保生效

[root@localhost ~]# partprobe

查看分区信息

[root@localhost ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0  200G  0 disk 
忖sda1            8:1    0  200M  0 part /boot
忖sda2            8:2    0 49.8G  0 part 
?忖centos-root 253:0    0 45.8G  0 lvm  /
?忖centos-swap 253:1    0    4G  0 lvm  [SWAP]
忖sda3            8:3    0  150G  0 part 
sr0              11:0    1 1024M  0 rom  
[root@localhost ~]# fdisk -l

Disk /dev/sda: 214.7 GB, 214748364800 bytes, 419430400 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000a3b4c

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      411647      204800   83  Linux
/dev/sda2          411648   104857599    52222976   8e  Linux LVM
/dev/sda3       104857600   419430399   157286400   8e  Linux LVM

2.格式化 /dev/sda3

[root@localhost ~]# mkfs.xfs /dev/sda3
meta-data=/dev/sda3              isize=512    agcount=4, agsize=9830400 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=39321600, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=19200, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

3.创建物理卷pv

[root@localhost ~]# pvdisplay 
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               centos
  PV Size               49.80 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              12749
  Free PE               0
  Allocated PE          12749
  PV UUID               7EnsrT-fESl-zmbK-3F1p-Y3rH-QZIz-m9oe1T

[root@localhost ~]# pvcreate /dev/sda3
WARNING: xfs signature detected on /dev/sda3 at offset 0. Wipe it? [y/n]: y
  Wiping xfs signature on /dev/sda3.
  Physical volume "/dev/sda3" successfully created.

[root@localhost ~]# pvdisplay 
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               centos
  PV Size               49.80 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              12749
  Free PE               0
  Allocated PE          12749
  PV UUID               7EnsrT-fESl-zmbK-3F1p-Y3rH-QZIz-m9oe1T
   
  --- Physical volume ---
  PV Name               /dev/sda3
  VG Name               centos
  PV Size               150.00 GiB / not usable 4.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              38399
  Free PE               0
  Allocated PE          38399
  PV UUID               YRcEFb-fW4e-GOKO-jjK2-QGyS-SRQ7-Uv3ZQu

4.将物理卷添加到卷组vg

[root@localhost ~]# vgdisplay 
  --- Volume group ---
  VG Name               centos
  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               49.80 GiB
  PE Size               4.00 MiB
  Total PE              12749
  Alloc PE / Size       12749 / 49.80 GiB
  Free  PE / Size       0 / 0   
  VG UUID               chkr0E-Tgym-oiZ3-3fsp-Fe4C-3EOT-fcZGiL

[root@localhost ~]# vgextend centos /dev/sda3
  Volume group "centos" successfully extended

[root@localhost ~]# vgdisplay 
  --- Volume group ---
  VG Name               centos
  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               <199.80 GiB
  PE Size               4.00 MiB
  Total PE              51148
  Alloc PE / Size       12749 / 49.80 GiB
  Free  PE / Size       38399 / <150.00 GiB
  VG UUID               chkr0E-Tgym-oiZ3-3fsp-Fe4C-3EOT-fcZGiL

5.扩容逻辑卷lv

[root@localhost ~]# lvdisplay 
  --- Logical volume ---
  LV Path                /dev/centos/swap
  LV Name                swap
  VG Name                centos
  LV UUID                sFhcD2-fltF-S1sY-p3Gu-OR2j-Entv-HJ1u0f
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-11-24 00:21:24 +0800
  LV Status              available
  # open                 2
  LV Size                4.00 GiB
  Current LE             1024
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/centos/root
  LV Name                root
  VG Name                centos
  LV UUID                VB75Pk-eCAN-gZtR-HboO-PBNF-1Kf9-Esw3dX
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-11-24 00:21:24 +0800
  LV Status              available
  # open                 1
  LV Size                45.80 GiB
  Current LE             11725
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0
   
[root@localhost ~]# lvextend -l +100%FREE /dev/centos/root
  Size of logical volume centos/root changed from 45.80 GiB (11725 extents) to <195.80 GiB (50124 extents).
  Logical volume centos/root successfully resized.

[root@localhost ~]# lvdisplay 
  --- Logical volume ---
  LV Path                /dev/centos/swap
  LV Name                swap
  VG Name                centos
  LV UUID                sFhcD2-fltF-S1sY-p3Gu-OR2j-Entv-HJ1u0f
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-11-24 00:21:24 +0800
  LV Status              available
  # open                 2
  LV Size                4.00 GiB
  Current LE             1024
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/centos/root
  LV Name                root
  VG Name                centos
  LV UUID                VB75Pk-eCAN-gZtR-HboO-PBNF-1Kf9-Esw3dX
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-11-24 00:21:24 +0800
  LV Status              available
  # open                 1
  LV Size                <195.80 GiB
  Current LE             50124
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

6.重新识别分区

[root@localhost ~]# xfs_growfs /dev/centos/root
meta-data=/dev/mapper/centos-root isize=512    agcount=4, agsize=3001600 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=12006400, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=5862, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 12006400 to 51326976

[root@localhost ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
devtmpfs                 7.8G     0  7.8G   0% /dev
tmpfs                    7.8G   60K  7.8G   1% /dev/shm
tmpfs                    7.8G  9.0M  7.8G   1% /run
tmpfs                    7.8G     0  7.8G   0% /sys/fs/cgroup
/dev/mapper/centos-root  196G  6.6G  190G   4% /
/dev/sda1                197M  166M   32M  84% /boot
tmpfs                    1.6G     0  1.6G   0% /run/user/1000
tmpfs                    1.6G     0  1.6G   0% /run/user/0

通过 df -h 命令可以看到根目录已成功扩容到200G，且扩容后无需重启机器，不得不说，lvm确认强。

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