Centos7扩展磁盘空间

1. 查看磁盘并创建新分区

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查看磁盘情况

fdisk -l

Disk /dev/sda: 85.9 GB, 85899345920 bytes, 167772160 sectors
#磁盘大小
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: 0x000bea13

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200    83886079    40893440   8e  Linux LVM

Disk /dev/mapper/centos-root: 39.7 GB, 39720058880 bytes, 77578240 
#分区大小
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

创建新分区

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              #n创建新分区
Partition type:
   p   primary (2 primary, 0 extended, 2 free)
   e   extended
Select (default p): p                #p分区类型
Partition number (3,4, default 3):   #直接回车
First sector (83886080-167772159, default 83886080):    #直接回车
Using default value 83886080
Last sector, +sectors or +size{K,M,G} (83886080-167772159, default 167772159):                          #直接回车
Using default value 167772159
Partition 3 of type Linux and of size 40 GiB is set
Command (m for help): w              #w保存并退出
The partition table has been altered!
Calling ioctl() to re-read partition table.

如果出现需要重新启动电脑

WARNING: Re-reading the partition table failed with error 16: 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(8) or kpartx(8)

reboot

再次查看分区

fdisk -l

Disk /dev/sda: 85.9 GB, 85899345920 bytes, 167772160 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: 0x000bea13

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200    83886079    40893440   8e  Linux LVM
/dev/sda3        83886080   167772159    41943040   83  Linux
#新增加磁盘分区 /dev/sda3 ,创建物理卷时使用
Disk /dev/mapper/centos-root: 39.7 GB, 39720058880 bytes, 77578240 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

2.创建物理卷并扩展卷组

查看卷组名称及大小

vgdisplay

  --- Volume group ---
  VG Name               centos               #名称
  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               <39.00 GiB大        #当前大小
  PE Size               4.00 MiB
  Total PE              9983
  Alloc PE / Size       9982 / 38.99 GiB    #已分配
  Free  PE / Size       1 / 4.00 MiB        #空闲大小扩展分区时使用
  VG UUID               HxuBfE-HjMo-oukD-Xx5T-g6zH-gjfE-pT48Kl

创建卷

pvcreate /dev/sda3

  Physical volume "/dev/sda3" successfully created.

扩展卷组

vgextend centos /dev/sda3

  Volume group "centos" successfully extended

查看物理卷

pvdisplay

  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               centos
  PV Size               <39.00 GiB / not usable 3.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              9983
  Free PE               1
  Allocated PE          9982
  PV UUID               1syFwI-rpjc-O1Ws-xGql-GC3o-tAml-OQIDsb

  --- Physical volume ---
  PV Name               /dev/sda3
  VG Name               centos
  PV Size               40.00 GiB / not usable 4.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              10239
  Free PE               10239
  Allocated PE          0
  PV UUID               wdIz6w-kwrN-BfcE-ECB1-JtdQ-PB5a-vcK0Eo

3.扩展逻辑卷

查看磁盘分区大小

df -h

Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root   37G  1.5G   36G   5% /      #需要扩展的分区
devtmpfs                 7.8G     0  7.8G   0% /dev
tmpfs                    7.8G     0  7.8G   0% /dev/shm
tmpfs                    7.8G  8.8M  7.8G   1% /run
tmpfs                    7.8G     0  7.8G   0% /sys/fs/cgroup
/dev/sda1               1014M  265M  750M  27% /boot
tmpfs                    1.6G     0  1.6G   0% /run/user/0

查看当前逻辑卷的名称及空间大小

lvdisplay

  --- Logical volume ---
  LV Path                /dev/centos/swap
  LV Name                swap
  VG Name                centos
  LV UUID                4PsjOD-0ASJ-ksHY-cK0w-HScG-Kg71-oGTMF3
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-05-15 05:16:38 -0400
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
 1. currently set to     8192
  Block device           253:1

  --- Logical volume ---
  LV Path                /dev/centos/root    #需要扩展的逻辑卷
  LV Name                root
  VG Name                centos
  LV UUID                h2q8Cv-Whlf-3Aav-80bd-14XC-1Cfg-wviAPB
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-05-15 05:16:39 -0400
  LV Status              available
  # open                 1
  LV Size                36.99 GiB
  Current LE             9470
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
 2. currently set to     8192
  Block device           253:0

3.扩展分区大小

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扩展分区

lvextend -l +10240 /dev/centos/root
+10240本次增加的容量，数值见查看卷组名称及大小vgdisplay

Size of logical volume centos/root changed from <40.90 GiB (10470 extents) to 76.99 GiB (19710 extents).
  Logical volume centos/root successfully resized.

调整文件系统大小 ext2、ext3、ext4文件系统

resize2fs -f /dev/centos/root

调整文件系统大小 xfs文件系统

xfs_growfs /dev/centos/root

查询分区大小

df -h

Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root   77G  1.5G   76G   2% /      #大小已经调整到位
devtmpfs                 7.8G     0  7.8G   0% /dev
tmpfs                    7.8G     0  7.8G   0% /dev/shm
tmpfs                    7.8G  8.8M  7.8G   1% /run
tmpfs                    7.8G     0  7.8G   0% /sys/fs/cgroup
/dev/sda1               1014M  265M  750M  27% /boot
tmpfs                    1.6G     0  1.6G   0% /run/user/0