云服务器创建LVM扩容，腾笼不换鸟

挂载新磁盘

故障

云服务器的业务出现故障，表现为上传图片失败，经过排查，由于磁盘的空间占满导致的文件写入失败。

服务器配置为8核心16GB，100GB系统盘和600GB数据盘。登录服务器查看，100GB挂载到/目录，600GB数据盘没有挂载没使用。

思路

解决思路，将600GB数据盘添加到逻辑卷，使用LVM方便以后扩容。挂载数据盘，迁移/OPT的数据到数据盘，移除/OPT目录，将数据盘挂载到/OPT，实现腾笼不换鸟。

注意事项

1. 操作前备份数据/打快照
2. 数据迁移操作需要业务停机，否则目录无法切换挂载。
3. 记得在/etc/fstab添加数据分区的挂载。
4. 谨慎操作，以防数据损坏。

查看磁盘容量

[root@ecs-3c08 images]# fdisk -l

Disk /dev/vda: 107.4 GB, 107374182400 bytes, 209715200 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: 0x000103c6

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1            2048     8390655     4194304   82  Linux swap / Solaris
/dev/vda2   *     8390656   209715166   100662255+  83  Linux

Disk /dev/vdb: 644.2 GB, 644245094400 bytes, 1258291200 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

/dev/vdb磁盘644.2GB

查看目录占用空间

[root@ecs-3c08 tcsf]# du -h --max-depth 1 ./ 2>/dev/null 
20K ./nginx-server
4.8M    ./nginx-wx
111M    ./backend-service
9.7M    ./nginx-manager
74G ./images
4.0K    ./files
12K ./nginx-proxy
74G ./
[root@ecs-3c08 images]# pwd
/opt/project/tcsf/images

查看块存储设备

[root@localhost ~]# lsblk -pf
NAME                        FSTYPE      LABEL UUID                                   MOUNTPOINT
/dev/sda                                                                             
├─/dev/sda1                 xfs               bd252330-2540-4705-bafa-0dc93532ab32   /boot
└─/dev/sda2                 LVM2_member       VYcAge-yo5K-QY8U-DcPD-VcMb-MbRq-IaLChR 
  ├─/dev/mapper/centos-root xfs               68864fee-0b10-4e28-9a80-11c18b4899b7   /
  └─/dev/mapper/centos-swap swap              385f00ee-abb2-4103-b13f-41fdc5b87123   [SWAP]
/dev/vdb     

将物理磁盘初始化为物理卷PV

[root@localhost ~]# pvcreate /dev/vdb 
  Physical volume "/dev/vdb" successfully created.
[root@localhost ~]# pvs
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sda2  centos lvm2 a--  <19.00g    0 
  /dev/sdb          lvm2 ---    1.00g 1.00g

创建卷组VG，将PV加入到VG中

[root@localhost ~]# vgcreate data /dev/vdb 
  Volume group "data" successfully created
[root@localhost ~]# vgs
  VG     #PV #LV #SN Attr   VSize    VFree   
  centos   1   2   0 wz--n-  <19.00g       0 
  data     1   0   0 wz--n- 1020.00m 1020.00m

基于VG创建逻辑卷LV

• -l：指定使用多少个VG中的LE创建LV，[%{VG|PVS|FREE}]

• -L：指定LV大小

• -n：指定LV名称

• -p：指定权限，r为只读，rw为读写

[root@localhost ~]# lvcreate -n opt  -l 100%vg  data
  Logical volume "opt" created.
[root@localhost ~]# lvs
  LV   VG     Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root centos -wi-ao----  <17.00g                                                    
  swap centos -wi-ao----    2.00g                                                    
  opt  data   -wi-a----- 1020.00m  

为逻辑卷创建文件系统

[root@localhost ~]# mkfs.xfs /dev/mapper/data-opt 
meta-data=/dev/mapper/data-opt   isize=512    agcount=4, agsize=65280 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=261120, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=855, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@localhost ~]# lsblk -pf
NAME                        FSTYPE      LABEL UUID                                   MOUNTPOINT
/dev/sda                                                                             
├─/dev/sda1                 xfs               bd252330-2540-4705-bafa-0dc93532ab32   /boot
└─/dev/sda2                 LVM2_member       VYcAge-yo5K-QY8U-DcPD-VcMb-MbRq-IaLChR 
  ├─/dev/mapper/centos-root xfs               68864fee-0b10-4e28-9a80-11c18b4899b7   /
  └─/dev/mapper/centos-swap swap              385f00ee-abb2-4103-b13f-41fdc5b87123   [SWAP]
/dev/sdb                    LVM2_member       EczTmf-bTPk-rRIr-C85A-hvcT-WZSn-Vxwt74 
└─/dev/mapper/data-opt      xfs               94b7ad5c-8e3a-4b5e-865a-4eb1fe717284   

创建挂载点，挂载LV

[root@localhost /]# mkdir opt1
[root@localhost /]# mount /dev/mapper/data-opt /opt1
[root@localhost /]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0   20G  0 disk 
├─sda1            8:1    0    1G  0 part /boot
└─sda2            8:2    0   19G  0 part 
  ├─centos-root 253:0    0   17G  0 lvm  /
  └─centos-swap 253:1    0    2G  0 lvm  [SWAP]
sdb               8:16   0    1G  0 disk 
└─data-opt      253:2    0 1020M  0 lvm  /opt1

迁移文件

cp -aR /opt/* /opt1/

迁移挂载目录

[root@localhost /]# mv /opt /opt2
[root@localhost /]# umount /opt1/
[root@localhost /]# ls /opt1/
[root@localhost /]# mkdir /opt
[root@localhost /]# mount /dev/mapper/data-opt /opt
[root@localhost /]# ls /opt/
1  2
[root@localhost /]# cat /opt/1 
new

开机自动挂载

在/etc/fstab添加自动挂载

#
# /etc/fstab
# Created by anaconda on Fri Mar  6 22:31:53 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=bd252330-2540-4705-bafa-0dc93532ab32 /boot                   xfs     defaults        0 0
/dev/mapper/centos-swap swap                    swap    defaults        0 0
/dev/mapper/data-opt /opt                       xfs     defaults        0 0