这是目前的磁盘情况

我查看了一下磁盘/dev/sda还有空余的空间

这种情况下,我只需要扩展vg的容量,然后给lv扩容即可,首先进行/dev/sda的磁盘分区,记得把新分的区改成8e

[root@centos7 ~]# fdisk /dev/sda

[root@centos7 ~]# partprobe /dev/sda #使kernel重新读取分区 信息，从而避免重启系统。

再次查看,发现已经分区了一块5G大小的空间

创建pv

[root@centos7 ~]# pvcreate /dev/sda3

Physical volume "/dev/sda3" successfully created.

扩展vg,首先先查看一下vg的信息,以免出错

[root@centos7 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

centos 1 3 0 wz--n- 12.00g 4.00m

[root@centos7 ~]# vgextend centos /dev/sda3

Volume group "centos" successfully extended

[root@centos7 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

centos 2 3 0 wz--n- 17.00g 5.00g

扩展lv,让lv的大小增加5G

[root@centos7 ~]# lvextend -L +5G /dev/mapper/centos-root

Size of logical volume centos/root changed from 5.00 GiB (1280 extents) to 10.00 GiB (2560 extents).

Logical volume centos/root successfully resized.

[root@centos7 ~]# xfs_growfs /dev/mapper/centos-root # 命令使系统重新读取大小

meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=327680 blks

= sectsz=512 attr=2, projid32bit=1

= crc=1 finobt=0 spinodes=0

data = bsize=4096 blocks=1310720, 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 1310720 to 2621440

查看效果,根目录已经扩容

[root@centos7 ~]# lvs

LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert

app centos -wi-ao---- 5.00g

root centos -wi-ao---- 10.00g

swap centos -wi-ao---- 2.00g

[root@centos7 ~]# df -h

文件系统 容量 已用 可用 已用% 挂载点

/dev/mapper/centos-root 10G 4.6G 5.4G 46% /

devtmpfs 471M 0 471M 0% /dev

tmpfs 488M 0 488M 0% /dev/shm

tmpfs 488M 21M 467M 5% /run

tmpfs 488M 0 488M 0% /sys/fs/cgroup

/dev/mapper/centos-app 5.0G 33M 5.0G 1% /app

/dev/sda1 97M 60M 38M 62% /boot

tmpfs 98M 12K 98M 1% /run/user/42

tmpfs 98M 0 98M 0% /run/user/0