Linux 下扩展磁盘分区

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我们在使用Linux作为虚拟机进行日常开发工作，经常会遇到某个磁盘空间不足的情况，这时通常需要进行扩容操作。

查看磁盘信息

查看磁盘使用状态

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[root@localhost ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
devtmpfs                 1.9G     0  1.9G   0% /dev
tmpfs                    1.9G     0  1.9G   0% /dev/shm
tmpfs                    1.9G   12M  1.9G   1% /run
tmpfs                    1.9G     0  1.9G   0% /sys/fs/cgroup
/dev/mapper/centos-root   18G   18G  9.2M 100% /
/dev/sda1                497M  169M  329M  34% /boot
/dev/sdb1                100G  1.8G   99G   2% /home
tmpfs                    378M     0  378M   0% /run/user/0

查看磁盘分区结构

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[root@localhost ~]# lsblk
NAME                       MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                          8:0    0   20G  0 disk
├─sda1                       8:1    0  500M  0 part /boot
└─sda2                       8:2    0 19.5G  0 part
  ├─centos-root            253:0    0 17.5G  0 lvm  /
  └─centos-swap            253:1    0    2G  0 lvm  [SWAP]
sdb                          8:16   0  100G  0 disk
└─sdb1                       8:17   0  100G  0 part /home
  • 由上面的信息可知，我们当前系统的根分区空间满了，需要进行扩容操作。

添加磁盘及分区

添加磁盘

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[root@localhost ~]# lsblk
NAME                       MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                          8:0    0   20G  0 disk
├─sda1                       8:1    0  500M  0 part /boot
└─sda2                       8:2    0 19.5G  0 part
  ├─centos-root            253:0    0 17.5G  0 lvm  /
  └─centos-swap            253:1    0    2G  0 lvm  [SWAP]
sdb                          8:16   0  100G  0 disk
└─sdb1                       8:17   0  100G  0 part /home
sdc                          8:32   0   50G  0 disk
  • 如上所示，我们添加了一块磁盘，sdc，未进行任何格式化或者分区操作

创建分区表

  • 由于磁盘空间只有50G，故这里对分区表没有要求，使用msdos或者GPT分区都行。注意如果空间大小超过了2TB，则必须采用GPT分区表。这里我们采用GPT分区表。
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# 创建GPT分区表
[root@localhost ~]# parted /dev/sdc  mklabel GPT
Information: You may need to update /etc/fstab.

# 查看磁盘信息
[root@localhost ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 53.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start  End  Size  File system  Name  Flags

创建分区

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# 创建一个主分区，分区起始地址为1MiB
[root@localhost ~]# parted /dev/sdc mkpart primary xfs 1MiB 100%FREE
Information: You may need to update /etc/fstab.

# 查看磁盘信息
[root@localhost ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 53.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name     Flags
 1      1049kB  53.7GB  53.7GB               primary
  • 由于我们的扩容策略是将该磁盘上所有的空间全部扩容到根分区，故这里我们只需要在该磁盘上创建一个分区，分区大小是整个磁盘的容量大小即可。这里采用了1MIB对齐。

扩容指定分区

创建物理卷

  • 分区扩容我们是通过逻辑卷来完成了，首先我们先在上面创建的分区上创建物理卷
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# 创建物理卷
[root@localhost ~]# pvcreate /dev/sdc1
  Physical volume "/dev/sdc1" successfully created.

# 查看物理卷信息
[root@localhost ~]# pvdisplay /dev/sdc1
  "/dev/sdc1" is a new physical volume of "<50.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdc1
  VG Name
  PV Size               <50.00 GiB
  Allocatable           NO
  PE Size               0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               0hRpcz-o6gQ-4MtD-MuGs-ltT3-RoVk-3E9Oc5

查找目标卷组

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# 查看逻辑卷信息
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/centos/swap
  LV Name                swap
  VG Name                centos
  LV UUID                60jdcJ-NQfJ-MT4K-rcrp-Gmbp-OY2S-gfdapy
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-07-08 05:32:48 +0800
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  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                0D5etc-7klz-Im4Y-GHAs-0O8W-mrCU-JZCXGY
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-07-08 05:32:49 +0800
  LV Status              available
  # open                 1
  LV Size                <17.47 GiB
  Current LE             4472
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0
  • 由于我们扩容的逻辑卷是 /dev/centos/root, 故其对应的卷组为centos，所以我们需要将新创建的物理卷 添加到centos这个卷组中

卷组扩容

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# 将物理卷 /dev/sdc1 添加到卷组centos中
[root@localhost ~]# vgextend centos /dev/sdc1
  Volume group "centos" successfully extended

# 查看卷组centos的信息
[root@localhost ~]# vgdisplay  centos
  --- Volume group ---
  VG Name               centos
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  5
  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               69.50 GiB
  PE Size               4.00 MiB
  Total PE              17793
  Alloc PE / Size       4984 / <19.47 GiB
  Free  PE / Size       12809 / <50.04 GiB
  VG UUID               j21OCZ-h3yM-KMAD-fUdc-2KxW-wM1p-qhxcoa


# 查看物理卷信息，此时物理卷信息中的卷组已经是centos了
[root@localhost ~]# pvdisplay /dev/sdc1
  --- Physical volume ---
  PV Name               /dev/sdc1
  VG Name               centos
  PV Size               <50.00 GiB / not usable 2.00 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              12799
  Free PE               12799
  Allocated PE          0
  PV UUID               0hRpcz-o6gQ-4MtD-MuGs-ltT3-RoVk-3E9Oc5

逻辑卷扩容

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# 逻辑卷扩容 50G
[root@localhost ~]# lvextend  -L "+50G" /dev/centos/root
  Size of logical volume centos/root changed from <17.47 GiB (4472 extents) to <67.47 GiB (17272 extents).
  Logical volume centos/root successfully resized.

# 查看逻辑卷信息
[root@localhost ~]# lvdisplay /dev/centos/root
  --- Logical volume ---
  LV Path                /dev/centos/root
  LV Name                root
  VG Name                centos
  LV UUID                0D5etc-7klz-Im4Y-GHAs-0O8W-mrCU-JZCXGY
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-07-08 05:32:49 +0800
  LV Status              available
  # open                 1
  LV Size                <67.47 GiB
  Current LE             17272
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

文件系统扩容

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# 对根分区的文件系统进行扩容
[root@localhost ~]# xfs_growfs /
meta-data=/dev/mapper/centos-root isize=256    agcount=4, agsize=1144832 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0 spinodes=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 17686528

# 查看分区大小
[root@localhost ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
devtmpfs                 1.9G     0  1.9G   0% /dev
tmpfs                    1.9G     0  1.9G   0% /dev/shm
tmpfs                    1.9G   12M  1.9G   1% /run
tmpfs                    1.9G     0  1.9G   0% /sys/fs/cgroup
/dev/mapper/centos-root   68G   18G   51G  26% /
/dev/sda1                497M  169M  329M  34% /boot
/dev/sdb1                100G  1.8G   99G   2% /home
tmpfs                    378M     0  378M   0% /run/user/0