前言
新的centos系统的时候，默认分区（如果你的磁盘比较大），他默认会把/根分区分50G，而把其他空间放到/home分区下面，这样的话你的根分区容量就太小了，很容易满，就造成了Centos7系统根分区空间小,/home空间大，那么怎么样把这个/home给他删除扩容到/根分区呢？
解决步骤
- 查看分区
[root@his ~]# df -Th
文件系统 类型 容量 已用 可用 已用% 挂载点
devtmpfs devtmpfs 4.2G 0 4.2G 0% /dev
tmpfs tmpfs 4.2G 0 4.2G 0% /dev/shm
tmpfs tmpfs 4.2G 21M 4.2G 1% /run
tmpfs tmpfs 4.2G 0 4.2G 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 50G 46G 4.2G 92% /
/dev/sda1 xfs 1014M 150M 865M 15% /boot
/dev/mapper/centos-home xfs 745G 2.3G 743G 1% /home
tmpfs tmpfs 860M 0 860M 0% /run/user/0
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/bedd245e5d20bdadbd56af18b9cd0c41e66963ccb0d072f37d1830119e3be190/merged
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/d28d7d3345cf9cc67bd1da0bd9fc0a9eade720865b8b9f4bd01ba41239ce2d06/merged
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/fa39b1dd91ee787c522977f6cf9366a836eea7800dbd062f42082d1e2ad126da/merged
2.分区表修改
删掉home分区或者注释掉
vi /etc/fstab
#
# /etc/fstab
# Created by anaconda on Mon Mar 8 09:39:01 2021
#
# 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
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=9b74bde6-6d0e-4b32-a1af-ac1e4ea927e9 /boot xfs defaults 0 0
#/dev/mapper/centos-home /home xfs defaults 0 0
/dev/mapper/centos-swap swap swap defaults 0 0
3.卸载掉/home分区,然后查看/home分区已经没有了（如果有数据，需要备份，我这里没有数据）
[root@his ~]# umount /home
[root@his ~]# df -Th
文件系统 类型 容量 已用 可用 已用% 挂载点
devtmpfs devtmpfs 4.2G 0 4.2G 0% /dev
tmpfs tmpfs 4.2G 0 4.2G 0% /dev/shm
tmpfs tmpfs 4.2G 21M 4.2G 1% /run
tmpfs tmpfs 4.2G 0 4.2G 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 50G 46G 4.2G 92% /
/dev/sda1 xfs 1014M 150M 865M 15% /boot
tmpfs tmpfs 860M 0 860M 0% /run/user/0
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/bedd245e5d20bdadbd56af18b9cd0c41e66963ccb0d072f37d1830119e3be190/merged
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/d28d7d3345cf9cc67bd1da0bd9fc0a9eade720865b8b9f4bd01ba41239ce2d06/merged
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/fa39b1dd91ee787c522977f6cf9366a836eea7800dbd062f42082d1e2ad126da/merged
4.查看有哪些lv逻辑分区
[root@his ~]# lvscan
ACTIVE '/dev/centos/swap' [4.31 GiB] inherit
ACTIVE '/dev/centos/home' [<744.68 GiB] inherit
ACTIVE '/dev/centos/root' [50.00 GiB] inherit
5.移除/home的lv分区
lvremove /dev/mapper/centos-home
#再看一下
[root@his ~]# lvscan
ACTIVE '/dev/centos/swap' [4.31 GiB] inherit
ACTIVE '/dev/centos/root' [50.00 GiB] inherit
6.查看一下vg的设置
[root@his ~]# vgdisplay
--- Volume group ---
VG Name centos
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 5
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 <799.00 GiB
PE Size 4.00 MiB
Total PE 204543
Alloc PE / Size 13904 / 54.31 GiB
Free PE / Size 190639 / 744.68 GiB
VG UUID poiSdH-FBDX-L8Qb-031s-cHw6-AVy7-qh8HPX
可以看到空闲出来的
Free PE / Size 190639 / 744.68 GiB
7.把空闲出来的全部扩展到根路径下
lvextend -l +100%free /dev/mapper/centos-root
#如果部分用大L，全部用小l
lvextend -L +1T /dev/mapper/centos-root
lvextend -L +200G /dev/mapper/centos-root
[root@his ~]# lvextend -l +100%free /dev/mapper/centos-root
Size of logical volume centos/root changed from 50.00 GiB (12800 extents) to 794.68 GiB (203439 extents).
Logical volume centos/root successfully resized.
扩容完成之后，他的容量还没有增加，我们需要刷新一下,需要执行一个命令
[root@his ~]# df -Th
文件系统 类型 容量 已用 可用 已用% 挂载点
devtmpfs devtmpfs 4.2G 0 4.2G 0% /dev
tmpfs tmpfs 4.2G 0 4.2G 0% /dev/shm
tmpfs tmpfs 4.2G 21M 4.2G 1% /run
tmpfs tmpfs 4.2G 0 4.2G 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 50G 46G 4.2G 92% /
/dev/sda1 xfs 1014M 150M 865M 15% /boot
tmpfs tmpfs 860M 0 860M 0% /run/user/0
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/bedd245e5d20bdadbd56af18b9cd0c41e66963ccb0d072f37d1830119e3be190/merged
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/d28d7d3345cf9cc67bd1da0bd9fc0a9eade720865b8b9f4bd01ba41239ce2d06/merged
overlay overlay 50G 46G 4.2G 92% /var/lib/docker/overlay2/fa39b1dd91ee787c522977f6cf9366a836eea7800dbd062f42082d1e2ad126da/merged
8.刷新,扩大/文件系统,时间长短看你的磁盘容量大小
#如果是centos7是xfs_growfs，如果是centos6是resize2fs
xfs_growfs /dev/mapper/centos-root
[root@his ~]# xfs_growfs /dev/mapper/centos-root
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=3276800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=13107200, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=6400, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 13107200 to 208321536
9.最后查看
[root@his ~]# df -Th
文件系统 类型 容量 已用 可用 已用% 挂载点
devtmpfs devtmpfs 4.2G 0 4.2G 0% /dev
tmpfs tmpfs 4.2G 0 4.2G 0% /dev/shm
tmpfs tmpfs 4.2G 21M 4.2G 1% /run
tmpfs tmpfs 4.2G 0 4.2G 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 795G 46G 749G 6% /
/dev/sda1 xfs 1014M 150M 865M 15% /boot
tmpfs tmpfs 860M 0 860M 0% /run/user/0
overlay overlay 795G 46G 749G 6% /var/lib/docker/overlay2/bedd245e5d20bdadbd56af18b9cd0c41e66963ccb0d072f37d1830119e3be190/merged
overlay overlay 795G 46G 749G 6% /var/lib/docker/overlay2/d28d7d3345cf9cc67bd1da0bd9fc0a9eade720865b8b9f4bd01ba41239ce2d06/merged
overlay overlay 795G 46G 749G 6% /var/lib/docker/overlay2/fa39b1dd91ee787c522977f6cf9366a836eea7800dbd062f42082d1e2ad126da/merged
