centos7下LVM挂载和扩容

说明：此操作在centos7下进行，如果是centos6发行版，需要注意格式化LV的文件系统类型（centos7.0开始默认文件系统是xfs，centos6是ext4）、最后一步写入系统的类型

查看当前磁盘

[root@fsddxtclgj9vm900419 ~]# df -Th

Filesystem              Type      Size  Used Avail Use% Mounted on

/dev/mapper/centos-root xfs        44G  3.7G   41G   9% /

devtmpfs                devtmpfs  7.8G     0  7.8G   0% /dev

tmpfs                   tmpfs     7.8G     0  7.8G   0% /dev/shm

tmpfs                   tmpfs     7.8G  777M  7.0G  10% /run

tmpfs                   tmpfs     7.8G     0  7.8G   0% /sys/fs/cgroup

/dev/vda1               xfs      1014M  179M  836M  18% /boot

tmpfs                   tmpfs     1.6G   36K  1.6G   1% /run/user/0

tmpfs                   tmpfs     1.6G   40K  1.6G   1% /run/user/1001

查看块分区

[root@fsddxtclgj9vm900419 ~]# lsblk

NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT

vda             252:0    0   50G  0 disk

├─vda1          252:1    0    1G  0 part /boot

└─vda2          252:2    0   49G  0 part

  ├─centos-root 253:0    0   44G  0 lvm  /

  └─centos-swap 253:1    0    5G  0 lvm  [SWAP]

vdb             252:16   0  974G  0 disk

可以看到 /dev/vdb 为新增的磁盘

格式化磁盘

[root@fsddxtclgj9vm900419 ~]# parted /dev/vdb

GNU Parted 3.1

Using /dev/vdb

Welcome to GNU Parted! Type 'help' to view a list of commands.

(parted) print

Error: /dev/vdb: unrecognised disk label

Model: Virtio Block Device (virtblk)

Disk /dev/vdb: 1046GB

Sector size (logical/physical): 512B/512B

Partition Table: unknown

Disk Flags:

(parted) mklabel gpt

(parted) mkpart primary 0 1045GB

Warning: The resulting partition is not properly aligned for best performance.

Ignore/Cancel? i

(parted) print

Model: Virtio Block Device (virtblk)

Disk /dev/vdb: 1046GB

Sector size (logical/physical): 512B/512B

Partition Table: gpt

Disk Flags: 

Number  Start   End     Size    File system  Name     Flags

 1      17.4kB  1045GB  1045GB               primary

(parted) set 1 lvm on

(parted) print

Model: Virtio Block Device (virtblk)

Disk /dev/vdb: 1046GB

Sector size (logical/physical): 512B/512B

Partition Table: gpt

Disk Flags: 

Number  Start   End     Size    File system  Name     Flags

 1      17.4kB  1045GB  1045GB               primary  lvm

(parted) quit

Information: You may need to update /etc/fstab

以上 (parted) 开头的代表输入的命令，具体功能可以通过 help 查看

重读分区表

partprobe /dev/vdb

重新查看块分区

[root@fsddxtclgj9vm900419 ~]# lsblk

NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT

vda             252:0    0    50G  0 disk

├─vda1          252:1    0     1G  0 part /boot

└─vda2          252:2    0    49G  0 part

  ├─centos-root 253:0    0    44G  0 lvm  /

  └─centos-swap 253:1    0     5G  0 lvm  [SWAP]

vdb             252:16   0   974G  0 disk

└─vdb1          252:17   0 973.2G  0 part

可以看到vdb下多了vdb1，这个用来创建pv

创建PV

[root@fsddxtclgj9vm900419 ~]# pvcreate -v /dev/vdb1

    Wiping internal VG cache

    Wiping cache of LVM-capable devices

    Wiping signatures on new PV /dev/vdb1.

    Set up physical volume for "/dev/vdb1" with 2041015592 available sectors.

    Zeroing start of device /dev/vdb1.

    Writing physical volume data to disk "/dev/vdb1".

  Physical volume "/dev/vdb1" successfully created.

注意

PV创建好之后，到这一步可以选择扩展或者新建挂载点，扩容的前提条件是扩容挂载点的磁盘格式是LVM格式，这里先演示新建挂载点然后删除挂载点并扩容

新增LVM挂载

查看PV

[root@fsddxtclgj9vm900419 ~]# pvdisplay

  --- Physical volume ---

  PV Name               /dev/vda2

  VG Name               centos

  PV Size               <49.00 GiB / not usable 3.00 MiB

  Allocatable           yes (but full)

  PE Size               4.00 MiB

  Total PE              12543

  Free PE               0

  Allocated PE          12543

  PV UUID               CCUeq0-ZnG9-iUY8-dPOj-fVOa-XC10-ooGyle

  "/dev/vdb1" is a new physical volume of "973.23 GiB"

  --- NEW Physical volume ---

  PV Name               /dev/vdb1

  VG Name

  PV Size               973.23 GiB

  Allocatable           NO

  PE Size               0

  Total PE              0

  Free PE               0

  Allocated PE          0

  PV UUID               vUoC7C-MIP2-iwXr-0SWu-c2Wz-yb6o-qFrfo1

注意看 VG Name，前面的是系统安装时选择LVM格式的，后面的还没有创建，所以 VG Name 为空

新建VG

[root@fsddxtclgj9vm900419 ~]# vgcreate -s 4M vg01 /dev/vdb1

  Volume group "vg01" successfully created

查看VG

[root@fsddxtclgj9vm900419 ~]# vgdisplay

  --- Volume group ---

  VG Name               vg01

  System ID

  Format                lvm2

  Metadata Areas        1

  Metadata Sequence No  1

  VG Access             read/write

  VG Status             resizable

  MAX LV                0

  Cur LV                0

  Open LV               0

  Max PV                0

  Cur PV                1

  Act PV                1

  VG Size               973.23 GiB

  PE Size               4.00 MiB

  Total PE              249147

  Alloc PE / Size       0 / 0

  Free  PE / Size       249147 / 973.23 GiB

  VG UUID               hb8zoy-kKjU-VXD5-EjCN-8hS2-MOzf-lq3O5j

  --- Volume group ---

  VG Name               centos

  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               <49.00 GiB

  PE Size               4.00 MiB

  Total PE              12543

  Alloc PE / Size       12543 / <49.00 GiB

  Free  PE / Size       0 / 0

  VG UUID               kSwsMj-4FKB-zwFq-7MBq-EfOD-rccg-HC59x9

可以看到 vg01 为新建的VG

新建LV

[root@fsddxtclgj9vm900419 ~]# lvcreate  -l 100%FREE -n lv01 vg01

  Logical volume "lv01" created

格式化LV

格式化文件系统类型有xfs，ext4，这里测试使用ext4格式，默认centos7下使用xfs格式，centos6为ext4格式

[root@fsddxtclgj9vm900419 ~]# mkfs.ext4 /dev/vg01/lv01

mke2fs 1.42.9 (28-Dec-2013)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

63782912 inodes, 255126528 blocks

12756326 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=2403336192

7786 block groups

32768 blocks per group, 32768 fragments per group

8192 inodes per group

Superblock backups stored on blocks:

        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,

        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,

        102400000, 214990848

Allocating group tables: done

Writing inode tables: done

Creating journal (32768 blocks): done

Writing superblocks and filesystem accounting information: done

新建挂载点并挂载

mkdir /app

mount /dev/vg01/lv01 /app

# 永久写入挂载点

# echo '/dev/vg01/lv01                            /app                    xfs     defaults        0 0' >> /etc/fstab

查看新增挂载后的块分区

[root@fsddxtclgj9vm900419 ~]# lsblk

NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT

vda             252:0    0    50G  0 disk

├─vda1          252:1    0     1G  0 part /boot

└─vda2          252:2    0    49G  0 part

  ├─centos-root 253:0    0    44G  0 lvm  /

  └─centos-swap 253:1    0     5G  0 lvm  [SWAP]

vdb             252:16   0   974G  0 disk

└─vdb1          252:17   0 973.2G  0 part

  └─vg01-lv01   253:2    0 973.2G  0 lvm  /app

可以看到新增磁盘以LVM格式挂载在 /app 下

删除LVM挂载点

删除挂载点

[root@fsddxtclgj9vm900419 ~]# umount -v /dev/vg01/lv01

umount: /app (/dev/mapper/vg01-lv01) unmounted

查看块设备

[root@fsddxtclgj9vm900419 ~]# lsblk

NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT

vda             252:0    0    50G  0 disk

├─vda1          252:1    0     1G  0 part /boot

└─vda2          252:2    0    49G  0 part

  ├─centos-root 253:0    0    44G  0 lvm  /

  └─centos-swap 253:1    0     5G  0 lvm  [SWAP]

vdb             252:16   0   974G  0 disk

└─vdb1          252:17   0 973.2G  0 part

  └─vg01-lv01   253:2    0 973.2G  0 lvm

可以看到 /app 挂载点删除了，删除 /app 目录

rm -rf /app

删除LV

参数为 LV Path

[root@fsddxtclgj9vm900419 ~]# lvremove /dev/vg01/lv01

Do you really want to remove active logical volume vg01/lv01? [y/n]: y

  Logical volume "lv01" successfully removed

删除VG

参数为 VG Name

[root@fsddxtclgj9vm900419 ~]# vgremove vg01

  Volume group "vg01" successfully removed

扩容VG

参数为 VG Name 和 PV Name

[root@fsddxtclgj9vm900419 ~]# vgextend centos /dev/vdb1

  Volume group "centos" successfully extended

此时 PV /dev/vdb1 全部扩展到 VG centos下

查看LV

[root@fsddxtclgj9vm900419 ~]# lvdisplay

  --- Logical volume ---

  LV Path                /dev/centos/swap

  LV Name                swap

  VG Name                centos

  LV UUID                PCx0yU-o9JZ-R92O-lI01-f8EU-DKyM-etst0H

  LV Write Access        read/write

  LV Creation host, time localhost.localdomain, 2018-12-24 16:46:31 +0800

  LV Status              available

  # open                 2

  LV Size                5.00 GiB

  Current LE             1280

  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                Idf9IO-AxkA-tS1C-FTgN-FsLT-d3Zk-7o1W5E

  LV Write Access        read/write

  LV Creation host, time localhost.localdomain, 2018-12-24 16:46:31 +0800

  LV Status              available

  # open                 1

  LV Size                <44.00 GiB

  Current LE             11263

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     8192

  Block device           253:0

通过查看，系统安装时选择的磁盘格式是LVM并且有两个分区，接下来扩展根分区

扩展LV分区

参数为 LV Path

[root@fsddxtclgj9vm900419 ~]# lvextend -l +100%FREE /dev/centos/root

  Size of logical volume centos/root changed from <44.00 GiB (11263 extents) to <1017.23 GiB (260410 extents).

  Logical volume centos/root successfully resized

如果发现误操作，需要还原，可以通过以下命令缩小LV分区

lvreduce -L 1017.2G  /dev/centos/root

加载扩容到系统

此时查看系统可以看到已经扩容，但没有加载到文件系统

[root@fsddxtclgj9vm900419 ~]# lsblk

NAME            MAJ:MIN RM    SIZE RO TYPE MOUNTPOINT

vda             252:0    0     50G  0 disk

├─vda1          252:1    0      1G  0 part /boot

└─vda2          252:2    0     49G  0 part

  ├─centos-root 253:0    0 1017.2G  0 lvm  /

  └─centos-swap 253:1    0      5G  0 lvm  [SWAP]

vdb             252:16   0    974G  0 disk

└─vdb1          252:17   0  973.2G  0 part

  └─centos-root 253:0    0 1017.2G  0 lvm  /

[root@fsddxtclgj9vm900419 ~]# df -h

Filesystem               Size  Used Avail Use% Mounted on

/dev/mapper/centos-root   44G  3.7G   41G   9% /

devtmpfs                 7.8G     0  7.8G   0% /dev

tmpfs                    7.8G     0  7.8G   0% /dev/shm

tmpfs                    7.8G  777M  7.0G  10% /run

tmpfs                    7.8G     0  7.8G   0% /sys/fs/cgroup

/dev/vda1               1014M  179M  836M  18% /boot

tmpfs                    1.6G   36K  1.6G   1% /run/user/0

tmpfs                    1.6G   40K  1.6G   1% /run/user/1001

加载扩容到系统

参数为 LV path，被扩容的挂载点一定是LVM格式

[root@fsddxtclgj9vm900419 ~]# xfs_growfs /dev/centos/root

meta-data=/dev/mapper/centos-root isize=512    agcount=4, agsize=2883328 blks

         =                       sectsz=512   attr=2, projid32bit=1

         =                       crc=1        finobt=0 spinodes=0

data     =                       bsize=4096   blocks=11533312, imaxpct=25

         =                       sunit=0      swidth=0 blks

naming   =version 2              bsize=4096   ascii-ci=0 ftype=1

log      =internal               bsize=4096   blocks=5631, version=2

         =                       sectsz=512   sunit=0 blks, lazy-count=1

realtime =none                   extsz=4096   blocks=0, rtextents=0

data blocks changed from 11533312 to 266659840

说明：若使用ext4文件格式（centos6），是使用resize2fs命令来生效

查看磁盘

[root@fsddxtclgj9vm900419 ~]# df -h

Filesystem               Size  Used Avail Use% Mounted on

/dev/mapper/centos-root 1018G  3.7G 1014G   1% /

devtmpfs                 7.8G     0  7.8G   0% /dev

tmpfs                    7.8G     0  7.8G   0% /dev/shm

tmpfs                    7.8G  777M  7.0G  10% /run

tmpfs                    7.8G     0  7.8G   0% /sys/fs/cgroup

/dev/vda1               1014M  179M  836M  18% /boot

tmpfs                    1.6G   36K  1.6G   1% /run/user/0

tmpfs                    1.6G   40K  1.6G   1% /run/user/1001