概述
从最底层向上，分别为：物理存储介质 > 物理卷（Physical Volume，PV） > 卷组（Volume Group，VG） > 逻辑卷（Logical Volume，LV）。
查看物理磁盘信息
[root@localhost ~]# fdisk -l
Disk /dev/sda: 107.4 GB, 107374182400 bytes, 209715200 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: 0x00035770
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 198549503 98761728 8e Linux LVM
Disk /dev/mapper/centos-root: 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 /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
Disk /dev/mapper/centos-home: 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 /dev/mapper/centos-data: 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 /dev/mapper/centos-mongo1: 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 /dev/mapper/centos-mongo2: 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
查看物理卷信息
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- 94.18g 2.18g
[root@localhost ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name centos
PV Size 94.19 GiB / not usable 3.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 24111
Free PE 559
Allocated PE 23552
PV UUID VZJK2P-I2xp-uBU7-GRT1-1lmv-AR7f-lvidpL
查看卷组信息
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 6 0 wz--n- 94.18g 2.18g
[root@localhost ~]# vgdisplay
--- Volume group ---
VG Name centos
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 19
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 6
Open LV 5
Max PV 0
Cur PV 1
Act PV 1
VG Size 94.18 GiB
PE Size 4.00 MiB
Total PE 24111
Alloc PE / Size 23552 / 92.00 GiB
Free PE / Size 559 / 2.18 GiB
VG UUID EnXv5G-61bc-tBOR-Zi6e-7Y8L-ygas-19p6jC
查看逻辑卷信息
[root@localhost ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
data centos -wi-ao---- 50.00g
home centos -wi-ao---- 10.00g
mongo1 centos -wi-ao---- 10.00g
mongo2 centos -wi-a----- 10.00g
root centos -wi-ao---- 10.00g
swap centos -wi-ao---- 2.00g
[root@localhost ~]# lvdisplay
--- Logical volume ---
LV Path /dev/centos/root
LV Name root
VG Name centos
LV UUID MOEifJ-qBRF-5gjB-qXB7-jNJa-LW3H-IzClIq
LV Write Access read/write
LV Creation host, time localhost, 2021-06-26 06:56:26 +0000
LV Status available
# open 1
LV Size 10.00 GiB
Current LE 2560
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
--- Logical volume ---
LV Path /dev/centos/home
LV Name home
VG Name centos
LV UUID 7NvaN8-X2k1-woTr-dvxF-ZvjL-OYsD-eX2lEn
LV Write Access read/write
LV Creation host, time localhost, 2021-06-26 06:56:27 +0000
LV Status available
# open 1
LV Size 10.00 GiB
Current LE 2560
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:2
--- Logical volume ---
LV Path /dev/centos/swap
LV Name swap
VG Name centos
LV UUID eEgY5U-bhWg-74Cl-AKWM-o3k4-9UBd-9NLg4K
LV Write Access read/write
LV Creation host, time localhost, 2021-06-26 06:56:27 +0000
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/data
LV Name data
VG Name centos
LV UUID FgxSlv-ISnS-0SKH-gTMk-gHCg-5xHh-n4F0yS
LV Write Access read/write
LV Creation host, time localhost, 2021-06-26 06:56:28 +0000
LV Status available
# open 1
LV Size 50.00 GiB
Current LE 12800
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:3
--- Logical volume ---
LV Path /dev/centos/mongo1
LV Name mongo1
VG Name centos
LV UUID 6wqmyQ-kII5-hXTa-E3Co-9iRU-626g-TAsUko
LV Write Access read/write
LV Creation host, time localhost, 2021-06-26 06:17:16 +0000
LV Status available
# open 1
LV Size 10.00 GiB
Current LE 2560
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:4
--- Logical volume ---
LV Path /dev/centos/mongo2
LV Name mongo2
VG Name centos
LV UUID 7hl3pj-ye17-1uNd-opVT-25SK-IZWa-iWd2EG
LV Write Access read/write
LV Creation host, time localhost, 2021-06-26 06:33:27 +0000
LV Status available
# open 0
LV Size 10.00 GiB
Current LE 2560
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:5
查看文件系统及挂载信息
[root@localhost ~]# df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 10G 1.3G 8.7G 14% /
devtmpfs devtmpfs 487M 0 487M 0% /dev
tmpfs tmpfs 497M 0 497M 0% /dev/shm
tmpfs tmpfs 497M 6.7M 490M 2% /run
tmpfs tmpfs 497M 0 497M 0% /sys/fs/cgroup
/dev/mapper/centos-home ext4 9.8G 37M 9.2G 1% /home
/dev/sda1 xfs 497M 125M 373M 25% /boot
tmpfs tmpfs 100M 0 100M 0% /run/user/0
/dev/mapper/centos-data ext4 50G 63M 47G 1% /data
/dev/mapper/centos-mongo1 ext4 9.8G 337M 8.9G 4% /mongo1
缩减逻辑卷
如果想新建逻辑卷，但卷组中已经没有空余空间，可以缩减已有的逻辑卷，切出一部分空间。
注意：centos默认的xfs格式磁盘，是不支持缩减的，会导致逻辑卷无法挂载，甚至系统无法启动。
- /data逻辑卷取消挂载。缩减前，要先将待缩减的卷取消挂载。
umount /data
- 检查卷
e2fsck -f /dev/centos/data
- 重置/dev/mapper/centos-data卷为10G
resize2fs /dev/centos/data 10G
lvresize -L 10G /dev/centos/data
- 重新挂载/etc/fstab中的所有卷
mount -a
新增卷
通过缩减逻辑卷，卷组中已经空余出37G的空间，可以通地vgs查看。
- 新增卷，指定大小为30G，名称为vnew，卷组为centos
lvcreate -L 30G -n vnew centos
- 查看新增的卷
lvdisplay
- 格式化新增的卷为ext4格式。
mkfs.ext4 /dev/centos/vnew
- 创建挂载点文件夹
mkdir /vnew/
- 编辑/etc/fstab，添加新增的卷。最后一行，添加如下内容：
/dev/centos/vnew /vnew ext4 defaults 0 0
- 重新挂载/etc/fstab中的所有卷。
mount -a
- 查看挂载情况
df -Th
删除卷
- 取消挂载
umount /vnew
- 删除卷
lvremove /dev/centos/vnew