Centos给根目录扩容教程

一、问题与目的

今天在使用nacos服务时发现怎么操作都会报错，原因是磁盘空间已满，正好有时间，研究一下怎么对Centos进行扩容

二、解决方法

1、首先，通过命令df -h 观察磁盘占用情况

可以发现根目录已经被写满了，这会导致所有写操作都无法进行

2、先关闭虚拟机，然后在VMware的设置中选择添加一块新的硬盘（一直点下一步就可以了）

我选择了扩容40G

3、重启虚拟机后通过命令lsblk可以发现多了一个分区sdb（原来只有sda）

所以接下来对sdb进行分区操作

4、对sdb进行分区操作

[root@itcast ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xdeeb604b.

Command (m for help): m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   g   create a new empty GPT partition table
   G   create an IRIX (SGI) partition table
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

Command (m for help): n                                #输入n新建一个分区
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p                                   #输入p,将分区创建为主分区
Partition number (1-4, default 1): 1    
First sector (2048-83886079, default 2048):             #默认     
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-83886079, default 83886079): 
Using default value 83886079
Partition 1 of type Linux and of size 40 GiB is set

Command (m for help): t                                #输入t改变分区类型
Selected partition 1
Hex code (type L to list all codes): 8e                #输入8e对应LVM
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): w                                #保存
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

再次观察发现有了sdb1分区

[root@itcast ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0   40G  0 disk 
├─sda1            8:1    0  200M  0 part /boot
└─sda2            8:2    0 39.8G  0 part 
  ├─centos-root 253:0    0   30G  0 lvm  /
  └─centos-swap 253:1    0  9.8G  0 lvm  [SWAP]
sdb               8:16   0   40G  0 disk 
└─sdb1            8:17   0   40G  0 part 
sr0              11:0    1 1024M  0 rom  

5、查看根分区的文件系统类型

6、格式化sdb1

[root@itcast ~]# mkfs.xfs /dev/sdb1
meta-data=/dev/sdb1              isize=512    agcount=4, agsize=2621376 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=10485504, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=5119, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

7、查看卷组信息（记住LV Path 和 VG Name）

8、开始扩容

[root@itcast ~]# pvcreate /dev/sdb1    #将sdb1分区变为pv
WARNING: xfs signature detected on /dev/sdb1 at offset 0. Wipe it? [y/n]: y
  Wiping xfs signature on /dev/sdb1.
  Physical volume "/dev/sdb1" successfully created.
[root@itcast ~]# vgextend centos /dev/sdb1    #将/dev/sdc1卷加入根目录所在的卷组名centos
  Couldn't create temporary archive name. ##报错啦！

发现报错了，"Couldn't create temporary archive name" 错误通常与 Logical Volume Manager (LVM) 中的缺少或损坏的临时文件有关。所以我们清理一下/tmp目录

执行 rm -rf /tmp/*

[root@itcast ~]# vgextend centos /dev/sdb1
  Volume group "centos" successfully extended

成功了

接着查看卷组信息 （记住Free PE）

把所有空间分配给根分区

[root@itcast ~]# lvextend -l +10239 /dev/centos/root    #10239=free pe
  Size of logical volume centos/root changed from 30.00 GiB (7680 extents) to <70.00 GiB (17919 extents).
  Logical volume centos/root successfully resized.

最后是文件系统的扩容

[root@itcast ~]# xfs_growfs /dev/centos/root
meta-data=/dev/mapper/centos-root isize=512    agcount=4, agsize=1966080 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=7864320, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=3840, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 7864320 to 18349056

Done！