Linux 根目录满了解决方法

最新推荐文章于 2025-10-21 15:42:16 发布

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本文详细记录了在Linux虚拟机中遇到根目录磁盘空间不足的问题，通过扩展磁盘、分区、创建物理卷、扩展卷组、调整逻辑卷大小，最终成功扩容根目录的过程。涉及的命令包括fdisk、pvcreate、vgextend、lvextend和xfs_growfs。

今天正在做一个实验,突然发现根目录满了,把这个过程记录下来(当初创建的时候给根目录分配的磁盘太小了.ahhhhh)

先关闭虚拟机电源，做如下设置：“ 虚拟机”–“虚拟机设置”–“磁盘”–“扩展
在这里插入图片描述

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
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.


Command (m for help): p

Disk /dev/sda: 16.1 GB, 16106127360 bytes
255 heads, 63 sectors/track, 1958 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        1305    10377990   8e  Linux LVM

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (1306-1958, default 1306): +1306
Last cylinder or +size or +sizeM or +sizeK (1306-1958, default 1958): +1958
Value out of range.
Last cylinder or +size or +sizeM or +sizeK (1306-1958, default 1958): 
Using default value 1958

Command (m for help): p

Disk /dev/sda: 16.1 GB, 16106127360 bytes
255 heads, 63 sectors/track, 1958 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        1305    10377990   8e  Linux LVM
/dev/sda3            1306        1958     5245222+  83  Linux

Command (m for help): t
Partition number (1,2, default 2): 3
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

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

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.

[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

[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