Centos7 LVM扩容实例

Centos7 lvm 扩容与以往版本有所不同

 

1.插入硬盘，我是在虚拟机上做的测试  直接添加一块5G的硬盘

 

2.系统读取硬盘信息

    # echo "- - -" > /sys/class/scsi_host/host0/scan

 

  查看结果 （红字为新加硬盘）
       # fdisk -l

 

Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 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: 0x000524cf

 

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *        2048     1026047      512000   83  Linux

/dev/sda2         1026048    41943039    20458496   8e  Linux LVM

 

Disk /dev/mapper/centos-root: 18.8 GB, 18756927488 bytes, 36634624 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 /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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 /dev/sdb: 5368 MB, 5368709120 bytes, 10485760 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

 

 

 

3.新加硬盘创建为 pv
      # pvcreate /dev/sdb 

  Physical volume "/dev/sdb" successfully created

[root@localhost host0]# pvdisplay 

  --- Physical volume ---

  PV Name               /dev/sda2

  VG Name               centos

  PV Size               19.51 GiB / not usable 3.00 MiB

  Allocatable           yes 

  PE Size               4.00 MiB

  Total PE              4994

  Free PE               10

  Allocated PE          4984

  PV UUID               z5e55H-j5bT-F1Op-cnpF-BPZQ-MQBS-OCZ9mK

   

  "/dev/sdb" is a new physical volume of "5.00 GiB"

  --- NEW Physical volume ---

  PV Name               /dev/sdb

  VG Name               

  PV Size               5.00 GiB

  Allocatable           NO

  PE Size               0   

  Total PE              0

  Free PE               0

  Allocated PE          0

  PV UUID               31hT9s-0YJG-io43-hcla-TPMq-2R5N-TOZexF

4.扩容vg

   vgextend vg名称  磁盘物理路径

# vgextend centos /dev/sdb 

   Volume group "centos" successfully extended

[root@localhost host0]# 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               24.50 GiB

  PE Size               4.00 MiB

  Total PE              6273

  Alloc PE / Size       4984 / 19.47 GiB

  Free  PE / Size       1289 / 5.04 GiB

  VG UUID               eD4mco-Sn0A-xt13-2g5h-Jttn-z1BZ-ZeHbJN

 

 

5.扩容lv

   lvextend -L  +扩容空间  lv名称

 # lvextend -L +5G /dev/centos/root 

             Size of logical volume centos/root changed from 17.47 GiB (4472 extents) to 22.47 GiB (5752 extents).

             Logical volume root successfully resized.

[root@localhost host0]# lvs

  LV   VG     Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert

  root centos -wi-ao---- 22.47g                                                    

  swap centos -wi-ao----  2.00g              

 

 

 

6.扩容文件系统 （注意！！！）

 resize2fs  lv路径名称

 

 # resize2fs /dev/centos/root      报错

resize2fs 1.42.9 (28-Dec-2013)

resize2fs: Bad magic number in super-block while trying to open /dev/centos/root

Couldn't find valid filesystem superblock.

 

 

以往的centos使用的文件系统是  ext2/ext3/ext4  
其对应的的调整命令是resize2fs

CentOS7.0的默认文件系统类型是 Xfs
其对应的调整命令是 xfs_growfs
不同文件系统类型对应的创建、检查、调整命令不同，要注意区分。

看下系统文件类型
# df -hT
Filesystem              Type      Size  Used Avail Use% Mounted on

/dev/mapper/centos-root         xfs            23G   1.4G  22G      6%  /

devtmpfs                devtmpfs  1.9G     0  1.9G   0% /dev
tmpfs                   tmpfs     1.9G     0  1.9G   0% /dev/shm
tmpfs                   tmpfs     1.9G  8.6M  1.9G   1% /run
tmpfs                   tmpfs     1.9G     0  1.9G   0% /sys/fs/cgroup
/dev/sda1               xfs       497M  125M  373M  26% /boot
tmpfs                   tmpfs     379M     0  379M   0% /run/user/0

使用新命令

# xfs_growfs /dev/centos/root

meta-data=/dev/mapper/centos-root isize=256 agcount=4, agsize=1144832 blks = sectsz=512 attr=2, projid32bit=1 = crc=0 finobt=0 data = bsize=4096 blocks=4579328, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 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 4579328 to 5890048 [root@localhost host0]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 23G 1.4G 22G 6% / devtmpfs 1.9G 0 1.9G 0% /dev tmpfs 1.9G 0 1.9G 0% /dev/shm tmpfs 1.9G 8.6M 1.9G 1% /run tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup /dev/sda1 497M 125M 373M 26% /boot tmpfs 379M 0 379M 0% /run/user/0

 

扩容成功！