物理机根分区/磁盘空间不足LVM在线扩容

突然遭遇/磁盘空间100%的尴尬，因为上面跑的有服务，不能添加硬件重启，我就查看了lsblk发现有一块硬盘/dev/sda有2T的空间，正好使用LVM在线扩容，开始吧... ...

第一步、先查看/etc/fstab里的/根分区是什么文件系统类型 ，这里用的是 xfs

/dev/mapper/cl-root     /                       xfs     defaults        0 0
UUID=1f24be8c-a592-4b7e-8e2c-416cd4a74d1d /boot                   xfs     defaults        0 0
UUID=E0C1-7ED8          /boot/efi               vfat    umask=0077,shortname=winnt 0 2
/dev/mapper/cl-home     /home                   xfs     defaults        0 0
/dev/mapper/cl-swap     none                    swap    defaults        0 0

 第二步、格式化/dev/sda3， 如果分区上包含了partition table分区表就需要-f去强制wirte 

# mkfs -t xfs /dev/sda
mkfs.xfs: /dev/sda appears to contain a partition table (gpt).
mkfs.xfs: Use the -f option to force overwrite.

# mkfs -t xfs -f /dev/sda3 
meta-data=/dev/sda3              isize=512    agcount=32, agsize=18285504 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1
data     =                       bsize=4096   blocks=585135104, imaxpct=5
         =                       sunit=64     swidth=128 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=285760, version=2
         =                       sectsz=512   sunit=64 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

第三步、创建PV

# pvs
  PV         VG Fmt  Attr PSize    PFree
  /dev/sdb3  cl lvm2 a--  <117.59g    0 

# pvcreate /dev/sda3
WARNING: xfs signature detected on /dev/sda3 at offset 0. Wipe it? [y/n]: y
  Wiping xfs signature on /dev/sda3.
  Physical volume "/dev/sda3" successfully created.

# pvs
  PV         VG Fmt  Attr PSize    PFree   
  /dev/sda3  cl lvm2 a--    <2.18t <184.11g
  /dev/sdb3  cl lvm2 a--  <117.59g       0 

第四步、增加PV到VG （能看到vg的变化从117G增加到2个多T）

# vgs
  WARNING: Couldn't find device with uuid dujV6z-4pEz-O2wD-MnnY-pW9c-YJaX-ifcImd.
  WARNING: VG centos is missing PV dujV6z-4pEz-O2wD-MnnY-pW9c-YJaX-ifcImd (last written to /dev/sdc1).
  VG     #PV #LV #SN Attr   VSize    VFree
  cl       1   3   0 wz--n- <117.59g    0 

# vgextend centos /dev/sda3
  Volume group "centos" not found
  Cannot process volume group centos

# vgs
  VG #PV #LV #SN Attr   VSize VFree   
  cl   2   3   0 wz--n- 2.29t <184.11g

第五步、扩展LVM

# lvs
  LV   VG Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  home cl -wi-ao---- <43.59g                                                    
  root cl -wi-ao----  70.00g                                                    
  swap cl -wi-ao----   4.00g 

# lvextend -L +2T /dev/cl/root 
  Size of logical volume cl/root changed from 70.00 GiB (17920 extents) to <2.07 TiB (542208 extents).
  Logical volume cl/root successfully resized.

# lvs
  LV   VG Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  home cl -wi-ao---- <43.59g                                                    
  root cl -wi-ao----  <2.07t                                                    
  swap cl -wi-ao----   4.00g   

第六步、更新文件系统 

• 如果使用xfs文件系统
  xfs_growfs /dev/root_vg/root
• 如果使用ext4文件系统
  resize2fs /dev/root_vg/root

# xfs_growfs /dev/cl/root
meta-data=/dev/mapper/cl-root    isize=512    agcount=4, agsize=4587520 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1
data     =                       bsize=4096   blocks=18350080, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=8960, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 18350080 to 555220992

# df -h
Filesystem           Size  Used Avail Use% Mounted on
devtmpfs             252G     0  252G   0% /dev
tmpfs                252G     0  252G   0% /dev/shm
tmpfs                252G   20M  252G   1% /run
tmpfs                252G     0  252G   0% /sys/fs/cgroup
/dev/mapper/cl-root  2.1T   83G  2.0T   4% /
/dev/mapper/cl-home   44G  384M   44G   1% /home
/dev/sdb2           1014M  237M  778M  24% /boot
/dev/sdb1            599M  7.3M  592M   2% /boot/efi
tmpfs                 51G   60K   51G   1% /run/user/1000

问题解决