RHEL/CentOS 调整分区大小

需求前提：

现有Linux机器，/ 分区大小不到50G或者刚好50G

现想减小其他分区的大小，然后对 / 分区进行扩容

 命令执行：

首先查看机器分区情况

[root@localhost ~] # df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root    50G  1.1G   49G   3% /
devtmpfs                 3.9G     0  3.9G   0%  /dev
tmpfs                    3.9G     0  3.9G   0%  /dev/shm
tmpfs                    3.9G   17M  3.9G   1%  /run
tmpfs                    3.9G     0  3.9G   0%  /sys/fs/cgroup
/dev/sda1                 494M  126M  369M  26%  /boot
/dev/mapper/centos-home    69G   33M   69G   1%  /home
tmpfs                    782M     0  782M   0%  /run/user/0

举例机器为centos系统，如果是RHEL， Filesystem对用的mapper大概为 rhel-home 样式

由分区情况可以看到/home的大小为69G，那就确定减小/home的大小，然后添加到 / 分区

 

 

有关备份的内容这里不再叙述，大家自己处理

取消挂载/home

[root@localhost ~] # umount /home
[root@localhost ~] # df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root    50G  1.1G   49G   3% /
devtmpfs                 3.9G     0  3.9G   0%  /dev
tmpfs                    3.9G     0  3.9G   0%  /dev/shm
tmpfs                    3.9G   17M  3.9G   1%  /run
tmpfs                    3.9G     0  3.9G   0%  /sys/fs/cgroup
/dev/sda1                 494M  126M  369M  26%  /boot
tmpfs                    782M     0  782M   0%  /run/user/0

删除/home所在的lv

[root@localhost ~] # lvremove /dev/mapper/centos-home
Do you really want to remove active logical volume home? [y /n ]: y
  Logical volume  "home"  successfully removed

扩展 / 分区lv，增加30G

[root@localhost ~] # lvextend -L +30G /dev/mapper/centos-root
  Size of logical volume centos /root  changed from 50.00 GiB (12800 extents) to 80.00 GiB (20480 extents).
  Logical volume root successfully resized.

扩展 / 分区文件系统

[root@localhost ~] # xfs_growfs /dev/mapper/centos-root
meta-data= /dev/mapper/centos-root  isize=256    agcount=4, agsize=3276800 blks
         =                       sectsz=4096  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=4096  sunit=1 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 13107200 to 20971520

重新创建 /home lv

[root@localhost ~] # lvcreate -L 39G -n /dev/mapper/centos-home
  Volume group  "centos"  has insufficient  free  space (9890 extents): 9984 required.
[root@localhost ~] # lvcreate -L 38G -n /dev/mapper/centos-home
  Logical volume  "home"  created.

注意这里，我第一次创建39G时，提示空间不足，所以创建了38G，这里根据实际容量动态调整即可

创建/home文件系统

[root@localhost ~] # mkfs.xfs /dev/mapper/centos-home
meta-data= /dev/mapper/centos-home  isize=256    agcount=4, agsize=2490368 blks
         =                       sectsz=4096  attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=9961472, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal log           bsize=4096   blocks=4864, version=2
         =                       sectsz=4096  sunit=1 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

挂载 /home

[root@localhost ~] # mount /dev/mapper/centos-home
[root@localhost ~] # df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root    80G  1.1G   79G   2% /
devtmpfs                 3.9G     0  3.9G   0%  /dev
tmpfs                    3.9G     0  3.9G   0%  /dev/shm
tmpfs                    3.9G   17M  3.9G   1%  /run
tmpfs                    3.9G     0  3.9G   0%  /sys/fs/cgroup
/dev/sda1                 494M  126M  369M  26%  /boot
tmpfs                    782M     0  782M   0%  /run/user/0
/dev/mapper/centos-home    38G   33M   38G   1%  /home

到这里，大功告成

Hope helpful