不重启增加centos根目录大小

矫情吗；* 2022-12-14 13:58 109阅读 0赞

# 添加新的磁盘 #

可以是在虚拟机上添加新磁盘，也可以在主机上插入新的磁盘。

一般来说，当我们在服务器上插入新的磁盘时，服务器是会对磁盘进行识别的。但是，有的时候服务器并没有对这些新插入的磁盘进行识别。这时，我们可以通过重启服务器，来使服务器重新加载硬盘。

在生产环境中我们的服务器上都存在着重要的服务，并不可以对服务器进行重启。下面介绍的就是**无需重启**服务器，使其识别新磁盘的方法。

# 发现新磁盘 #

fdisk -l

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3hndzEwMTA_size_16_color_FFFFFF_t_70_pic_center]  
里面没有新加的磁盘。

## 查看主机总线号 ##

ls /sys/class/scsi\_host/  
![在这里插入图片描述][20201014114814695.png_pic_center]

## 重新扫描SCSI总线添加设备 ##

echo "- - -" > /sys/class/scsi_host/host0/scan
    echo "- - -" > /sys/class/scsi_host/host1/scan
    echo "- - -" > /sys/class/scsi_host/host2/scan

## 查看磁盘是否扫描出来 ##

fdisk -l

# 对磁盘进行分区 #

fdisk /dev/sdb
    
    　　fdisk的交互模式，依次输入
    　　
    n  --创建新分区
    p  --创建主分区
    <回车>  --默认分区编号
    <回车>  --默认起始扇区位置。
    <回车>  --默认结束扇区位置。
    t  --设置分区类型
    8e  类型为LVM
    w  --写入分区表

再查看磁盘情况

[root@localhost Desktop]# fdisk -l /dev/sdb
    
    Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk label type: dos
    Disk identifier: 0xf0480a7c
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048    41943039    20970496   8e  Linux LVM

> 注意  
> 新分区的类型是`Linux LVM`

# 扩充根分区 #

## 查看卷分组 ##

[root@localhost Desktop]# vgdisplay -v ##找到centos
        Using volume group(s) on command line.
      --- Volume group ---
      VG Name               centos
      System ID             
      Format                lvm2
      Metadata Areas        1
      Metadata Sequence No  4
      VG Access             read/write
      VG Status             resizable
      MAX LV                0
      Cur LV                3
      Open LV               3
      Max PV                0
      Cur PV                1
      Act PV                1
      VG Size               99.51 GiB
      PE Size               4.00 MiB
      Total PE              25474
      Alloc PE / Size       25458 / 99.45 GiB
      Free  PE / Size       16 / 64.00 MiB
      VG UUID               eajt4v-Jdef-HZmX-U6AL-kOTp-lc1w-nHXcBe

## 为新增的分区创建物理卷 ##

[root@localhost Desktop]# pvcreate /dev/sdb1
    ##提示是否擦除xfs签名，可以根据实际情况选择
    WARNING: ext4 signature detected on /dev/sdb1 at offset 1080. Wipe it? [y/n]: y
      Wiping ext4 signature on /dev/sdb1.
      Physical volume "/dev/sdb1" successfully created

查看结果

[root@localhost Desktop]# pvdisplay /dev/sdb1##可以看到新创建的20GiB大小的物理卷：
      "/dev/sdb1" is a new physical volume of "20.00 GiB"
      --- NEW Physical volume ---
      PV Name               /dev/sdb1
      VG Name               
      PV Size               20.00 GiB
      Allocatable           NO
      PE Size               0   
      Total PE              0
      Free PE               0
      Allocated PE          0
      PV UUID               JSpfvR-zsge-XRVU-CRT2-ubec-LcmO-oZtxmD

## 扩展卷分组 ##

"centos"是vgdisplay命令查到的卷分组名

[root@localhost Desktop]# vgextend centos /dev/sdb1
      Volume group "centos" successfully extended

# 查看逻辑卷，并扩展逻辑卷 #

[root@registry mnt]# lvdisplay
      --- Logical volume ---
      LV Path                /dev/centos/swap
      LV Name                swap
      VG Name                centos
      LV UUID                pv0FXb-ADjF-qe8D-tXzo-T4sE-3MVH-YncDVN
      LV Write Access        read/write
      LV Creation host, time localhost.localdomain, 2018-11-08 16:41:14 +0800
      LV Status              available
      # open 2
      LV Size                <7.88 GiB
      Current LE             2016
      Segments               1
      Allocation             inherit
      Read ahead sectors     auto
      - currently set to     8192
      Block device           253:1
       
      --- Logical volume ---
      LV Path                /dev/centos/home
      LV Name                home
      VG Name                centos
      LV UUID                PEfA9A-3uOV-ocwc-Xr09-kk3p-2pqT-ssR24H
      LV Write Access        read/write
      LV Creation host, time localhost.localdomain, 2018-11-08 16:41:15 +0800
      LV Status              available
      # open 1
      LV Size                23.48 GiB
      Current LE             6011
      Segments               1
      Allocation             inherit
      Read ahead sectors     auto
      - currently set to     8192
      Block device           253:2
       
      --- Logical volume ---
      LV Path                /dev/centos/root
      LV Name                root
      VG Name                centos
      LV UUID                7NDe7m-rUYa-HqEn-qs2p-Zhth-Ww0h-VgtOAp
      LV Write Access        read/write
      LV Creation host, time localhost.localdomain, 2018-11-08 16:41:18 +0800
      LV Status              available
      # open 1
      LV Size                <48.09 GiB
      Current LE             12311
      Segments               1
      Allocation             inherit
      Read ahead sectors     auto
      - currently set to     8192
      Block device           253:0

可以看到/dev/centos/root目前的LV Size是48.09G。

[root@localhost Desktop]# lvextend -L +20G /dev/centos/root
    Size of logical volume centos/root changed from 50.00 GiB (12800 extents) to 53.00 GiB (13568 extents).
    Logical volume root successfully resized.

## 扩展后执行 ##

[root@localhost Desktop]# xfs_growfs /dev/centos/root
    meta-data=/dev/mapper/centos-root isize=256    agcount=4, agsize=3276800 blks
             =                       sectsz=512   attr=2, projid32bit=1
             =                       crc=0        finobt=0
    data     =                       bsize=4096   blocks=13107200, imaxpct=25
             =                       sunit=0      swidth=0 blks
    naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
    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 13893632

将文件系统扩大，完成。

## 查看结果 ##

[root@localhost Desktop]# df -hT

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3hndzEwMTA_size_16_color_FFFFFF_t_70_pic_center]: /images/20221123/a19e706626cf41279a12f20abda50290.png
[20201014114814695.png_pic_center]: /images/20221123/5fdb75a1273f4a5b88e0f7993e3eeead.png