Linux-磁盘扩容 从新磁盘扩容(PV) 单块硬盘调整默认分区

从新磁盘扩容(PV)

假设我们再增加一块硬盘为 /dev/sdd1

[root@192 /]# pvcreate /dev/sdd1
Physical volume "/dev/sdd1" successfully created.
[root@192 /]# pvdisplay
--- Physical volume ---
PV Name               /dev/sdd1
VG Name               data
PV Size               465.76 GiB / not usable 3.02 MiB
Allocatable           yes (but full)
PE Size               4.00 MiB
Total PE              119234
Free PE               0
Allocated PE          119234
PV UUID               2JuybS-xzUQ-h7q5-hzLF-fFqv-UzU3-G3ZozC

如果在虚拟机中添加SCSI格式的磁盘做PV时出现如下报错：

root@host1:~# pvcreate /dev/sdb
Device /dev/sdb excluded by a filter.

导致问题的原因是添加的磁盘是在另一个虚拟机中新建的，已经有了分区表，现在的虚拟机并不能识别磁盘的分区表，运行parted命令重做分区表，中途需要输入三次命令。

root@host1:~# parted /dev/sdb
GNU Parted 3.2
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel msdos
Warning: The existing disk label on /dev/sdb will be destroyed and all data on this disk will be lost. Do you want to continue?
Yes/No? yes
(parted) quit
Information: You may need to update /etc/fstab.

再次运行pvcreate，问是否擦除dos签名，输入y，就可以将磁盘创建为PV了。

root@host1:~# pvcreate /dev/sdb
WARNING: dos signature detected on /dev/sdb at offset 510. Wipe it? [y/n]: y
Wiping dos signature on /dev/sdb.
Physical volume "/dev/sdb" successfully created.

将新磁盘加入一个分组

[root@192 /]# vgextend data /dev/sdd1
Volume group "data" successfully extended
[root@192 /]# vgdisplay
--- Volume group ---
VG Name               data
System ID
Format                lvm2
Metadata Areas        4
Metadata Sequence No  5
VG Access             read/write
VG Status             resizable
MAX LV                0
Cur LV                1
Open LV               1
Max PV                0
Cur PV                4
Act PV                4
VG Size               <1.82 TiB    //这里会发现容量已经增大了
PE Size               4.00 MiB
Total PE              476936
Alloc PE / Size       348160 / <1.33 TiB
Free  PE / Size       128776 / 503.03 GiB
VG UUID               hqdEd1-03aQ-zMsd-fPeV-JluL-0joY-jXhdGu

为现有磁盘扩充容量

[root@192 /]# lvextend -l +100%FREE /dev/data/mylv
Size of logical volume data/mylv changed from <1.33 TiB (348160 extents) to <1.82 TiB (476936 extents).
Logical volume data/mylv successfully resized.
[root@192 /]# lvdisplay
--- Logical volume ---
LV Path                /dev/data/mylv
LV Name                mylv
VG Name                data
LV UUID                jGXCJR-HdxT-XXQx-Yhyb-0vM0-VyN2-8gRweb
LV Write Access        read/write
LV Creation host, time 192.168.0.104, 2019-02-14 10:30:47 +0800
LV Status              available
# open                 1
LV Size                <1.82 TiB    //逻辑卷的容量也扩容了
Current LE             476936
Segments               4
Allocation             inherit
Read ahead sectors     auto
- currently set to     256
Block device           253:2

查看磁盘容量以及刷新磁盘容量

[root@192 /]# df -Th
[root@192 /]# resize2fs /dev/data/mylv #CentOS7中报错
[root@192 /]# xfs_growfs /dev/data/mylv #CentOS7中可使用

单块硬盘调整默认分区

centos7在安装时若是自动分区，“/”分区默认只有50G，大部分空间会分给”/home”，安装完系统可以将“/home”删掉全部挂在/下，首先解除/home的挂载

umount /home

删除home所在LV

lvremove /dev/centos/home

扩容“/”所在LV

lvextend -l +100%FREE /dev/centos/root

扩展root文件系统(只能扩容，不能缩容)

xfs_growfs /dev/centos/root

修改fstab（这一步非常重要，千万不要漏了）

vim /etc/fstab

注释或者删除/dev/mapper/centos-home /home

#
# /etc/fstab
# Created by anaconda on Thu Jul 16 22:43:55 2020
#
# 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=de0e00f9-c956-46bb-bcf4-e2d057b9c0d4 /boot                   xfs     defaults        0 0
UUID=7AB3-D1FB          /boot/efi               vfat    umask=0077,shortname=winnt 0 0
# /dev/mapper/centos-home /home                   xfs     defaults        0 0
/dev/mapper/centos-swap swap                    swap    defaults        0 0

就是记个笔记参考博客链接：
https://www.geek-share.com/detail/2719755769.html
https://blog.csdn.net/weixin_41558061/article/details/87286680
https://blog.csdn.net/lhl3620/article/details/104792408/