以虛擬機為例
1、在虛擬機上添加新磁盤，點擊虛擬機→設置->添加，最后如下圖。
2、進入系統fdisk -l，查看當前磁盤信息
[root@master shell]# fdisk -l Disk /dev/sda: 10.7 GB, 10737418240 bytes, 20971520 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: 0x000af178 Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 20971519 9436160 8e Linux LVM Disk /dev/mapper/centos-root: 8585 MB, 8585740288 bytes, 16769024 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: 1073 MB, 1073741824 bytes, 2097152 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 [root@master shell]#
發現沒有讀到我們新添加的磁盤，我們重啟下虛擬機。
如果不想重啟，或者是生產上的服務器，不允許重啟，可以使用partprobe，在線更新分區表。
# partprobe在線更新分區信息表，獲取最新的磁盤信息 [root@master ~]# partprobe
重新使用fdisk -l命令查看，發現多了一塊21.5GB的/dev/sdb磁盤
# fdisk -l 重新查看一下 [root@master ~]# df -Th Filesystem Type Size Used Avail Use% Mounted on devtmpfs devtmpfs 475M 0 475M 0% /dev tmpfs tmpfs 487M 0 487M 0% /dev/shm tmpfs tmpfs 487M 7.5M 479M 2% /run tmpfs tmpfs 487M 0 487M 0% /sys/fs/cgroup /dev/mapper/centos-root xfs 8.0G 4.8G 3.3G 60% / /dev/sda1 xfs 1014M 167M 848M 17% /boot tmpfs tmpfs 98M 0 98M 0% /run/user/0 [root@master ~]# fdisk -l Disk /dev/sda: 10.7 GB, 10737418240 bytes, 20971520 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: 0x000af178 Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 20971519 9436160 8e Linux LVM Disk /dev/sdb: 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 /dev/mapper/centos-root: 8585 MB, 8585740288 bytes, 16769024 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: 1073 MB, 1073741824 bytes, 2097152 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、fdisk在新的磁盤上創建分區
[root@master ~]# fdisk /dev/sdb # 注意，這里的sdb是不帶數字的
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.
Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xe1f69387.
Command (m for help): n # new新建分區
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p # 選擇主分區
Partition number (1-4, default 1): 1 # 分區編號，直接回車，選擇默認的1就好
First sector (2048-41943039, default 2048): # 設置起始扇區，直接回車，選擇默認的
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): # 設置結束扇區，直接回車，默認選擇到磁盤的最后一個扇區。
Using default value 41943039 # 默認分區的容量就是整個磁盤的容量
Partition 1 of type Linux and of size 20 GiB is set
Command (m for help): p # print打印當前設置好的磁盤信息（注意，此時還沒物理生效）
Disk /dev/sdb: 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: 0xe1f69387
Device Boot Start End Blocks Id System
/dev/sdb1 2048 41943039 20970496 83 Linux
Command (m for help): t # 輸入t，修改磁盤格式為LVM格式
Selected partition 1
Hex code (type L to list all codes): 8e # 輸入8e，8e代表LVM格式
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p # 再次打印磁盤信息
Disk /dev/sdb: 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: 0xe1f69387
Device Boot Start End Blocks Id System
/dev/sdb1 2048 41943039 20970496 8e Linux LVM
Command (m for help): w # w開始保存設置的磁盤分區信息，此時才是真正作用生效了。
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
4、創建pv
創建LVM概念中的物理卷。
注意：這里要選帶數字編號的磁盤，這里的/dev/sdb1就是上面我們用fdisk創建好的磁盤分區，1表示我們的分區編號，上面設置的是1，所以這里就是sdb1
[root@master ~]# pvscan # 查看當前系統上的物理卷信息 PV /dev/sda2 VG centos lvm2 [<9.00 GiB / 0 free] Total: 1 [<9.00 GiB] / in use: 1 [<9.00 GiB] / in no VG: 0 [0 ] [root@master ~]# pvcreate /dev/sdb1 # 創建物理卷，注意這里的磁盤尾號sdb1必須帶數字 Physical volume "/dev/sdb1" successfully created. [root@master ~]# pvscan PV /dev/sda2 VG centos lvm2 [<9.00 GiB / 0 free] PV /dev/sdb1 lvm2 [<20.00 GiB] Total: 2 [<29.00 GiB] / in use: 1 [<9.00 GiB] / in no VG: 1 [<20.00 GiB]
5、將pv加入vg組，擴容vg
pv是物理卷，vg是卷組，多個pv組成一個vg，然后vg里面去構建邏輯卷組lv
如果系統沒有vg，則創建vg組。
[root@master ~]# vgdisplay
[root@master ~]# vgscan
Reading volume groups from cache.
# vgcreate 后面可以接多個磁盤，比如vgcreate vgdata /dev/xvde1 /dev/xvde2，因為這里只有一塊，所以就用一個
[root@master ~]# vgcreate vgdata /dev/xvde1 # 創建vg，vg名字設置為vgdata，/dev/xvde1是我們上面創建的pv卷的名字
Volume group "vgdata" successfully created
[root@master ~]# vgscan
Reading volume groups from cache.
Found volume group "vgdata" using metadata type lvm2
[root@master ~]# vgdisplay
--- Volume group ---
VG Name vgdata
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 <300.00 GiB
PE Size 4.00 MiB
Total PE 76799
Alloc PE / Size 0 / 0
Free PE / Size 76799 / <300.00 GiB
VG UUID bY9vpW-ALyF-YDxB-WCjj-Tlvg-04Jp-DWXdkm
[root@master ~]#
如果有vg，則擴容
[root@master ~]# vgdisplay
--- 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 <9.00 GiB
PE Size 4.00 MiB
Total PE 2303
Alloc PE / Size 2303 / <9.00 GiB
Free PE / Size 0 / 0
VG UUID YSauT8-zhj2-05Yc-c4rb-VNqs-OjrX-ZB8eeE
[root@master ~]# vgextend centos /dev/sdb1 # centos是原來就已經存在的卷組名字，/dev/sdb1是我們剛剛創建的pv名字
Volume group "centos" successfully extended
[root@master ~]# 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 28.99 GiB
PE Size 4.00 MiB
Total PE 7422
Alloc PE / Size 2303 / <9.00 GiB
Free PE / Size 5119 / <20.00 GiB
VG UUID YSauT8-zhj2-05Yc-c4rb-VNqs-OjrX-ZB8eeE
6、擴容LV
如果LV邏輯卷不存在，則創建
[root@yzjgxh2529638940 ~]# lvcreate -n lvdata -L 300G vgdata
Volume group "vgdata" has insufficient free space (76799 extents): 76800 required.
# 一般無法用到300G,所以稍微小一點就好了
[root@yzjgxh2529638940 ~]# lvcreate -n lvdata -L 299G vgdata
Logical volume "lvdata" created.
[root@yzjgxh2529638940 ~]# lvscan
ACTIVE '/dev/vgdata/lvdata' [299.00 GiB] inherit
[root@yzjgxh2529638940 ~]#
# 格式化該邏輯分區
[root@yzjgxh2529638940 ~]# mkfs.xfs /dev/vgdata/lvdata
meta-data=/dev/vgdata/lvdata isize=512 agcount=4, agsize=19595264 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=78381056, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=38272, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@yzjgxh2529638940 ~]#
如果LV邏輯卷存在，則擴容
[root@master ~]# lvscan ACTIVE '/dev/centos/swap' [1.00 GiB] inherit ACTIVE '/dev/centos/root' [<8.00 GiB] inherit [root@master ~]# lvextend -L +19.5G /dev/centos/root Size of logical volume centos/root changed from <8.00 GiB (2047 extents) to <27.50 GiB (7039 extents). Logical volume centos/root successfully resized.
7、resize使文件系統生效（重要）
[root@master ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 475M 0 475M 0% /dev
tmpfs tmpfs 487M 0 487M 0% /dev/shm
tmpfs tmpfs 487M 7.5M 479M 2% /run
tmpfs tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 8.0G 4.8G 3.3G 60% /
/dev/sda1 xfs 1014M 167M 848M 17% /boot
tmpfs tmpfs 98M 0 98M 0% /run/user/0
# ext3,ext4使用resize2fs
[root@master ~]# resize2fs /dev/centos/root
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.
# 這里需要擴容的是xfs，所以用xfs_growfs命令
[root@master ~]# xfs_growfs /dev/centos/root
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=524032 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=2096128, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
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 2096128 to 7207936
[root@master ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 475M 0 475M 0% /dev
tmpfs tmpfs 487M 0 487M 0% /dev/shm
tmpfs tmpfs 487M 7.5M 479M 2% /run
tmpfs tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 28G 4.8G 23G 18% /
/dev/sda1 xfs 1014M 167M 848M 17% /boot
tmpfs tmpfs 98M 0 98M 0% /run/user/0
8、掛載
# 創建掛載的目錄 [root@yzjgxh2529638940 ~]# mkdir /data # 開始掛載 [root@yzjgxh2529638940 ~]# mount /dev/vgdata/lvdata /data/ [root@yzjgxh2529638940 ~]# df -Th Filesystem Type Size Used Avail Use% Mounted on /dev/xvda2 xfs 36G 2.1G 34G 6% / devtmpfs devtmpfs 32G 0 32G 0% /dev tmpfs tmpfs 32G 24K 32G 1% /dev/shm tmpfs tmpfs 32G 18M 32G 1% /run tmpfs tmpfs 32G 0 32G 0% /sys/fs/cgroup tmpfs tmpfs 6.3G 0 6.3G 0% /run/user/0 /dev/mapper/vgdata-lvdata xfs 299G 33M 299G 1% /data # 加入開機自動掛載 [root@yzjgxh2529638940 ~]# vim /etc/fstab # # /etc/fstab # Created by anaconda on Thu May 9 01:56:05 2019 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # UUID=a83f4fdc-2ea1-4fec-a1e2-a42016ce0afe / xfs defaults 0 0 UUID=9e33bd6f-c68c-41c7-95c8-703f4fe8c3d4 swap swap defaults 0 0 /dev/vgdata/lvdata /data xfs defaults 0 0
到此，LVM擴容完成。