LVM是Linux系统中对磁盘分区进行管理的一种逻辑机制，它是建立在硬盘和分区之上、文件系统之下的一个逻辑层，在建立文件系统时屏蔽了下层的磁盘分区布局，能够在保持现有数据不变的情况下动态调整磁盘容量，从而提高磁盘管理的灵活性。
其实系统默认就有这个卷组：
[root@localhost ~]# vgdisplay
--- Volume group ---
VG Name VolGroup
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 99.51 GiB
PE Size 4.00 MiB
Total PE 25474
Alloc PE / Size 25474 / 99.51 GiB
Free PE / Size 0 / 0
VG UUID o0Udpv-BvUO-R3n2-BpAE-QvWx-pfzf-JA83jC
交换分区、根分区默认就使用了逻辑卷：
[root@localhost ~]# lvdisplay
--- Logical volume ---
LV Path /dev/VolGroup/lv_root
LV Name lv_root
VG Name VolGroup
LV UUID JA8Vxw-hPXh-yW2t-XOon-5vqj-uuUy-4QaW4s
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-07-05 04:34:18 +0800
LV Status available
# open 1
LV Size 95.51 GiB
Current LE 24450
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Path /dev/VolGroup/lv_swap
LV Name lv_swap
VG Name VolGroup
LV UUID UYnjVa-nCqs-hTN1-1ZbV-3z2L-lpGs-Inh1oW
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-07-05 04:34:24 +0800
LV Status available
# open 1
LV Size 4.00 GiB
Current LE 1024
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
查看根分区所使用的逻辑卷：
[root@localhost ~]# lvdisplay /dev/VolGroup/lv_root
--- Logical volume ---
LV Path /dev/VolGroup/lv_root
LV Name lv_root
VG Name VolGroup
LV UUID JA8Vxw-hPXh-yW2t-XOon-5vqj-uuUy-4QaW4s
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-07-05 04:34:18 +0800
LV Status available
# open 1
LV Size 95.51 GiB
Current LE 24450
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
############
扩大根分区
虚拟机添加一块硬盘：
备注：服务器重启后，才能识别新硬盘。
查看第二块硬盘的分区情况：
fdisk -l /dev/sdb
创建物理卷：
[root@localhost ~]# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created
扩大卷组：
[root@localhost ~]# vgextend VolGroup /dev/sdb
Volume group "VolGroup" successfully extended
[root@localhost ~]# vgdisplay
--- Volume group ---
VG Name VolGroup
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 129.50 GiB
PE Size 4.00 MiB
Total PE 33153
Alloc PE / Size 25474 / 99.51 GiB
Free PE / Size 7679 / 30.00 GiB
VG UUID o0Udpv-BvUO-R3n2-BpAE-QvWx-pfzf-JA83jC
扩展逻辑卷（不能把空间全部分完，要留0.1G！）
[root@localhost ~]# lvextend -L +29.9G /dev/VolGroup/lv_root
Rounding size to boundary between physical extents: 29.90 GiB.
Size of logical volume VolGroup/lv_root changed from 95.51 GiB (24450 extents) to 125.41 GiB (32105 extents).
Logical volume lv_root successfully resized.
逻辑卷扩展成功：
[root@localhost ~]# lvdisplay /dev/VolGroup/lv_root
--- Logical volume ---
LV Path /dev/VolGroup/lv_root
LV Name lv_root
VG Name VolGroup
LV UUID JA8Vxw-hPXh-yW2t-XOon-5vqj-uuUy-4QaW4s
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-07-05 04:34:18 +0800
LV Status available
# open 1
LV Size 125.41 GiB
Current LE 32105
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
重建EXT4文件系统：
[root@localhost ~]# resize2fs /dev/VolGroup/lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/VolGroup/lv_root is mounted on /; on-line resizing required
old desc_blocks = 6, new_desc_blocks = 8
Performing an on-line resize of /dev/VolGroup/lv_root to 32875520 (4k) blocks.
The filesystem on /dev/VolGroup/lv_root is now 32875520 blocks long.
根分区扩展成功：
备注：根分区扩展无需重启系统；重启系统后，系统也正常。
相关文章：
CentOS8_LVM_扩大根分区 |
