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 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 +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 /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 -hTFilesystem              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% /devtmpfs                   tmpfs     1.9G     0  1.9G   0% /dev/shmtmpfs                   tmpfs     1.9G  8.6M  1.9G   1% /runtmpfs                   tmpfs     1.9G     0  1.9G   0% /sys/fs/cgroup/dev/sda1               xfs       497M  125M  373M  26% /boottmpfs                   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=0data     =                       bsize=4096   blocks=4579328, imaxpct=25         =                       sunit=0      swidth=0 blksnaming   =version 2              bsize=4096   ascii-ci=0 ftype=0log      =internal               bsize=4096   blocks=2560, version=2         =                       sectsz=512   sunit=0 blks, lazy-count=1realtime =none                   extsz=4096   blocks=0, rtextents=0data blocks changed from 4579328 to 5890048[root@localhost host0]# df -hFilesystem               Size  Used Avail Use% Mounted on/dev/mapper/centos-root   23G  1.4G   22G   6% /devtmpfs                 1.9G     0  1.9G   0% /devtmpfs                    1.9G     0  1.9G   0% /dev/shmtmpfs                    1.9G  8.6M  1.9G   1% /runtmpfs                    1.9G     0  1.9G   0% /sys/fs/cgroup/dev/sda1                497M  125M  373M  26% /boottmpfs                    379M     0  379M   0% /run/user/0

扩容成功！