Centos7扩展磁盘空间（LVM管理）

vmware或hyperv，扩容磁盘，本例中使用的是vmware,关闭系统，在vmware—>设置—>硬盘—>扩展—>输入数字大于当前系统内存—>点击扩展,如图：

1. 查看磁盘情况

fdisk -l /dev/sda

Disk /dev/sda: 536.9 GB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk label type: dos
Disk identifier: 0x000ac88a

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *                       Linux
/dev/sda2                  8e  Linux LVM

2. 查看磁盘占用情况

df -lh

Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/cl-root   50G   24G   27G  % /
devtmpfs             .8G       .8G   % /dev
tmpfs                .8G   84K  .8G   % /dev/shm
tmpfs                .8G  8.8M  .8G   % /run
tmpfs                .8G       .8G   % /sys/fs/cgroup
/dev/sda1           1014M  173M  842M  % /boot
/dev/mapper/cl-home   69G  517M   68G   % /home
tmpfs                .2G   16K  .2G   % /run/user/
tmpfs                .2G       .2G   % /run/user/

3. 创建新分区

fdisk /dev/sda

弹出的命令行中输入对应的命令，命令说明如下：

Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)

a) 命令行输入 n 创建新分区

[root@lenmom ~]# fdisk /dev/sda

The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.
Welcome to fdisk (util-linux 2.23.).

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

Command (m for help): n

b) 命令行输入 p 设置分区类型为主分区

Command (m for help): n
Partition type:
   p   primary ( primary,  extended,  free)
   e   extended
Select (default p): p

c) 设置分区数量，这里输入为

Command (m for help): n
Partition type:
   p   primary ( primary,  extended,  free)
   e   extended
Select (default p): p
Partition number (,, default ): 

d)修改分区大小，我们这里取默认大小，直接按两次回车即可（开始和结束位置）

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

e) 输入t修改分区编号

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

Command (m for help): t
Partition number (-, default ): 

f）修改分区编号为3

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

Command (m for help): t
Partition number (-, default ):
Hex code (type L to list all codes): 

 g) 选择分区格式,我们选择lvm，所以输入8e

Hex code (type L to list all codes):     L

   Empty             NEC DOS           Minix / old Lin bf  Solaris
   FAT12             Hidden NTFS Win   Linux swap / So c1  DRDOS/sec (FAT-
   XENIX root        Plan             Linux           c4  DRDOS/sec (FAT-
   XENIX usr       3c  PartitionMagic    OS/ hidden C:  c6  DRDOS/sec (FAT-
   FAT16 <32M        Venix        Linux extended  c7  Syrinx
   Extended          PPC PReP Boot     NTFS volume set da  Non-FS data
   FAT16             SFS               NTFS volume set db  CP/M / CTOS / .
   HPFS/NTFS/exFAT 4d  QNX4.x            Linux plaintext de  Dell Utility
   AIX             4e  QNX4.x 2nd part 8e  Linux LVM       df  BootIt
   AIX bootable    4f  QNX4.x 3rd part   Amoeba          e1  DOS access
 a  OS/ Boot Manag   OnTrack DM        Amoeba BBT      e3  DOS R/O
 b  W95 FAT32         OnTrack DM6 Aux 9f  BSD/OS          e4  SpeedStor
 c  W95 FAT32 (LBA)   CP/M            a0  IBM Thinkpad hi eb  BeOS fs
 e  W95 FAT16 (LBA)   OnTrack DM6 Aux a5  FreeBSD         ee  GPT
 f  W95 Ext'd (LBA) 54  OnTrackDM6      a6  OpenBSD         ef  EFI (FAT-12/16/
  OPUS              EZ-Drive        a7  NeXTSTEP        f0  Linux/PA-RISC b
  Hidden FAT12      Golden Bow      a8  Darwin UFS      f1  SpeedStor
  Compaq diagnost 5c  Priam Edisk     a9  NetBSD          f4  SpeedStor
  Hidden FAT16 <   SpeedStor       ab  Darwin boot     f2  DOS secondary
  Hidden FAT16      GNU HURD or Sys af  HFS / HFS+      fb  VMware VMFS
  Hidden HPFS/NTF   Novell Netware  b7  BSDI fs         fc  VMware VMKCORE
  AST SmartSleep    Novell Netware  b8  BSDI swap       fd  Linux raid auto
1b  Hidden W95 FAT3   DiskSecure Mult bb  Boot Wizard hid fe  LANstep
1c  Hidden W95 FAT3   PC/IX           be  Solaris boot    ff  BBT
1e  Hidden W95 FAT1   Old Minix
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

h) 输入w保存分区并退出

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

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error : Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe() or kpartx()
Syncing disks.

4. 重启系统

reboot

5. 查看已有卷组名

vgdisplay

  --- Volume group ---
  VG Name               cl
  System ID
  Format                lvm2
  Metadata Areas
  Metadata Sequence No
  VG Access             read/write
  VG Status             resizable
  MAX LV
  Cur LV
  Open LV
  Max PV
  Cur PV
  Act PV
  VG Size               <126.00 GiB
  PE Size               4.00 MiB
  Total PE
  Alloc PE / Size        / 125.99 GiB
  Free  PE / Size        / 4.00 MiB
  VG UUID               zlg3Lh-rWHl-ozXP-FfIL-xs2w-yT7a-2k3VgA

在本机中卷组为cl.(后面会用到)

6. 为新分配的空间创建一个新的物理卷

pvcreate /dev/sda3

  Physical volume "/dev/sda3" successfully created.

注意：如果出现错误说pvcreate命令找不到，则执行：

yum install pv

7. 使用新的物理卷来扩展 LVM 的 VolGroup

vgextend cl /dev/sda3

这里的cl即为第5步中查出来的卷组名. 命令执行输出如下：

[root@lenmom ~]# vgextend cl /dev/sda3
  Volume group "cl" successfully extended

8. 扩展 LVM 的逻辑卷 /dev/cl/home

a) 先查看逻辑卷集合

lvdisplay

输出如下：

[root@lenmom ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/cl/swap
  LV Name                swap
  VG Name                cl
  LV UUID                LM5xZa-J1Af-XPIu-CQYK-2JTw-Cw9N-JOmqdm
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, -- :: +
  LV Status              available
  # open
  LV Size                <7.88 GiB
  Current LE
  Segments
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to
  Block device           :

  --- Logical volume ---
  LV Path                /dev/cl/home
  LV Name                home
  VG Name                cl
  LV UUID                U2TrdQ-ihpb-SNr3-U1cq-qOKr-4gw0-rYNmOG
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, -- :: +
  LV Status              available
  # open
  LV Size                <68.12 GiB
  Current LE
  Segments
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to
  Block device           :

  --- Logical volume ---
  LV Path                /dev/cl/root
  LV Name                root
  VG Name                cl
  LV UUID                xXKaHg-WKW0-H3e2-dtjx-MJLS-bUcm-PpPw3z
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, -- :: +
  LV Status              available
  # open
  LV Size                50.00 GiB
  Current LE
  Segments
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to
  Block device           :

这里我们选择扩展/dev/cl/home逻辑卷

b）扩展逻辑卷/dev/cl/home空间

lvextend  /dev/cl/home  /dev/sda3

输出为：

[root@lenmom ~]# lvextend  /dev/cl/home  /dev/sda3
  Size of logical volume cl/home changed from <68.12 GiB ( extents) to 441.11 GiB ( extents).
  Logical volume cl/home successfully resized.

可以看到原有的磁盘空间从68G扩展到了441G,

lvextend参数-L是指定大小 如果不输入-L +10G 则默认使用全部

9）调整逻辑卷的大小

xfs_growfs /dev/cl/home

输出为：

[root@lenmom ~]# xfs_growfs /dev/cl/home
meta-data=/dev/mapper/cl-home isize=512 agcount=4, agsize=4464128 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=17856512, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=8719, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 17856512 to 115635200

注意：

有些地方说要使用resize2fs命令更新系统识别的文件系统大小，但是亲测要使用xfs_growfs命令。

10） 检验结果

[root@lenmom ~]# lvscan
  ACTIVE            '/dev/cl/swap' [<7.88 GiB] inherit
  ACTIVE            '/dev/cl/home' [441.11 GiB] inherit
  ACTIVE            '/dev/cl/root' [50.00 GiB] inherit

也可以使用下面的方式来检验

[root@palolenmom ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/cl-root   50G   14G   37G  % /
devtmpfs             .8G       .8G   % /dev
tmpfs                .8G   84K  .8G   % /dev/shm
tmpfs                .8G  8.7M  .8G   % /run
tmpfs                .8G       .8G   % /sys/fs/cgroup
/dev/sda1           1014M  173M  842M  % /boot
/dev/mapper/cl-home  442G   23G  419G   % /home
tmpfs                .2G   16K  .2G   % /run/user/
tmpfs                .2G       .2G   % /run/user/