Linux 系统盘的根 / 是 LVM，使用系统盘所在的物理硬盘中未使用的空间进行扩容：
文本在图片下面
[root@centos7-2009 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 898M 0 898M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.6M 901M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 47G 1.3G 46G 3% /
/dev/sda1 1014M 150M 865M 15% /boot
tmpfs 182M 0 182M 0% /run/user/0
[root@centos7-2009 ~]# 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: 0x000a25d9
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 104857599 51379200 8e Linux LVM
Disk /dev/mapper/centos-root: 50.5 GB, 50457477120 bytes, 98549760 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
[root@centos7-2009 ~]# 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
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p): p
Partition number (3,4, default 3): 3
First sector (104857600-167772159, default 104857600):
Using default value 104857600
Last sector, +sectors or +size{K,M,G} (104857600-167772159, default 167772159):
Using default value 167772159
Partition 3 of type Linux and of size 30 GiB is set
Command (m for help): t
Partition number (1-3, default 3):
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p
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: 0x000a25d9
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 104857599 51379200 8e Linux LVM
/dev/sda3 104857600 167772159 31457280 8e Linux LVM
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 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)
Syncing disks.
[root@centos7-2009 ~]# ll /dev/sda*
brw-rw----. 1 root disk 8, 0 Sep 20 19:24 /dev/sda
brw-rw----. 1 root disk 8, 1 Sep 20 19:24 /dev/sda1
brw-rw----. 1 root disk 8, 2 Sep 20 19:24 /dev/sda2
[root@centos7-2009 ~]# reboot
Connection closing...Socket close.
Connection closed by foreign host.
Disconnected from remote host(192.168.61.140) at 11:25:12.
Type `help' to learn how to use Xshell prompt.
[C:\~]$
Connecting to 192.168.61.140:22...
Connection established.
To escape to local shell, press 'Ctrl+Alt+]'.
WARNING! The remote SSH server rejected X11 forwarding request.
Last login: Tue Sep 20 19:25:45 2022 from 192.168.61.1
[root@centos7-2009 ~]# ll /dev/sda*
brw-rw----. 1 root disk 8, 0 Sep 20 19:25 /dev/sda
brw-rw----. 1 root disk 8, 1 Sep 20 19:25 /dev/sda1
brw-rw----. 1 root disk 8, 2 Sep 20 19:25 /dev/sda2
brw-rw----. 1 root disk 8, 3 Sep 20 19:25 /dev/sda3
[root@centos7-2009 ~]# 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: 0x000a25d9
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 104857599 51379200 8e Linux LVM
/dev/sda3 104857600 167772159 31457280 8e Linux LVM
Disk /dev/mapper/centos-root: 50.5 GB, 50457477120 bytes, 98549760 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
[root@centos7-2009 ~]# df -T /dev/sda1
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/sda1 xfs 1038336 153592 884744 15% /boot
[root@centos7-2009 ~]# mkfs.ext4 /dev/sda3
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
1966080 inodes, 7864320 blocks
393216 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2155872256
240 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
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
[root@centos7-2009 ~]# pvcreate /dev/sda3
WARNING: ext4 signature detected on /dev/sda3 at offset 1080. Wipe it? [y/n]: y
Wiping ext4 signature on /dev/sda3.
Physical volume "/dev/sda3" successfully created.
[root@centos7-2009 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos
PV Size <49.00 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 12543
Free PE 1
Allocated PE 12542
PV UUID blYys0-jLwd-uNLn-0y5Q-9Ymi-ecCg-zCjccL
"/dev/sda3" is a new physical volume of "30.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sda3
VG Name
PV Size 30.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID HfSyAk-E37q-o23Z-J7fC-wZMY-q38L-av48iv
[root@centos7-2009 ~]# vgextend centos /dev/sda3
Volume group "centos" successfully extended
[root@centos7-2009 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos
PV Size <49.00 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 12543
Free PE 1
Allocated PE 12542
PV UUID blYys0-jLwd-uNLn-0y5Q-9Ymi-ecCg-zCjccL
--- Physical volume ---
PV Name /dev/sda3
VG Name centos
PV Size 30.00 GiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 7679
Free PE 7679
Allocated PE 0
PV UUID HfSyAk-E37q-o23Z-J7fC-wZMY-q38L-av48iv
[root@centos7-2009 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 2 2 0 wz--n- 78.99g 30.00g
[root@centos7-2009 ~]# lvextend -l +100%FREE /dev/mapper/centos-root
Size of logical volume centos/root changed from 46.99 GiB (12030 extents) to 76.99 GiB (19710 extents).
Logical volume centos/root successfully resized.
[root@centos7-2009 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 898M 0 898M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.6M 901M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 47G 1.3G 46G 3% /
/dev/sda1 1014M 150M 865M 15% /boot
tmpfs 182M 0 182M 0% /run/user/0
[root@centos7-2009 ~]# xfs_growfs /
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=3079680 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=12318720, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=6015, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 12318720 to 20183040
[root@centos7-2009 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 898M 0 898M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.6M 901M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 77G 1.3G 76G 2% /
/dev/sda1 1014M 150M 865M 15% /boot
tmpfs 182M 0 182M 0% /run/user/0
[root@centos7-2009 ~]#
Linux 系统盘的根 / 是 LVM，新增物理硬盘进行扩容：
文本在图片下面
[root@centos7-2009 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 898M 0 898M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.6M 901M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 47G 1.3G 46G 3% /
/dev/sda1 1014M 150M 865M 15% /boot
tmpfs 182M 0 182M 0% /run/user/0
[root@centos7-2009 ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000a25d9
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 104857599 51379200 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: 50.5 GB, 50457477120 bytes, 98549760 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
[root@centos7-2009 ~]# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created.
[root@centos7-2009 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos
PV Size <49.00 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 12543
Free PE 1
Allocated PE 12542
PV UUID blYys0-jLwd-uNLn-0y5Q-9Ymi-ecCg-zCjccL
"/dev/sdb" is a new physical volume of "20.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb
VG Name
PV Size 20.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID Nq2B5X-bEg0-UjV5-CIsU-26hK-w83d-KqKsx6
[root@centos7-2009 ~]# vgextend centos /dev/sdb
Volume group "centos" successfully extended
[root@centos7-2009 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos
PV Size <49.00 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 12543
Free PE 1
Allocated PE 12542
PV UUID blYys0-jLwd-uNLn-0y5Q-9Ymi-ecCg-zCjccL
--- Physical volume ---
PV Name /dev/sdb
VG Name centos
PV Size 20.00 GiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 5119
Free PE 5119
Allocated PE 0
PV UUID Nq2B5X-bEg0-UjV5-CIsU-26hK-w83d-KqKsx6
[root@centos7-2009 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 2 2 0 wz--n- 68.99g 20.00g
[root@centos7-2009 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 898M 0 898M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.6M 901M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 47G 1.3G 46G 3% /
/dev/sda1 1014M 150M 865M 15% /boot
tmpfs 182M 0 182M 0% /run/user/0
[root@centos7-2009 ~]# lvextend -l +100%FREE /dev/mapper/centos-root
Size of logical volume centos/root changed from 46.99 GiB (12030 extents) to 66.99 GiB (17150 extents).
Logical volume centos/root successfully resized.
[root@centos7-2009 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 898M 0 898M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.6M 901M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 47G 1.3G 46G 3% /
/dev/sda1 1014M 150M 865M 15% /boot
tmpfs 182M 0 182M 0% /run/user/0
[root@centos7-2009 ~]# xfs_growfs /
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=3079680 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=12318720, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=6015, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 12318720 to 17561600
[root@centos7-2009 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 898M 0 898M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.6M 901M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 67G 1.3G 66G 2% /
/dev/sda1 1014M 150M 865M 15% /boot
tmpfs 182M 0 182M 0% /run/user/0
[root@centos7-2009 ~]#
说明：如果执行
xfs_growfs /提示xfs_growfs: / is not a mounted XFS filesystem，则需要使用resize2fs /dev/mapper/centos-root**