[系统运维]Linux分配home的磁盘空间给根目录

系统安装完成以后，根目录的磁盘空间只有70G，剩余的大部分空间会分配到/home目录下面。使用过程中很少使用到/home目录，所以我们来把/home目录的磁盘空间分配一些给根目录

扩容之前备份

查看磁盘使用情况

[root@itranCentOS /]# df -h
文件系统                         容量  已用  可用 已用% 挂载点
devtmpfs                          28G     0   28G    0% /dev
tmpfs                             28G     0   28G    0% /dev/shm
tmpfs                             28G   18M   28G    1% /run
tmpfs                             28G     0   28G    0% /sys/fs/cgroup
/dev/mapper/cl_itrancentos-root   70G  5.2G   65G    8% /
/dev/sda2                       1014M  238M  777M   24% /boot
/dev/mapper/cl_itrancentos-home  1.8T   13G  1.8T    1% /home
/dev/sda1                        599M  7.3M  592M    2% /boot/efi
tmpfs                            5.5G   36K  5.5G    1% /run/user/1000

卸载/home目录

umount /home 或者 umount /dev/mapper/vg_rogear-lv_home

[root@itranCentOS /]# umount /home
umount: /home: target is busy.
[root@itranCentOS /]# umount /dev/mapper/cl_itrancentos-root
umount: /: target is busy.

如果出现以上信息，表明还有进程在占用home分区，执行如下命令

[root@itranCentOS /]# fuser -m /home/
/home:                7243m  7261c  7265cm  7294c  7386cm  7418c  7423c  7475cm  7480c  7483c  7572cm  7666c  7670cm  7671cm  7674c  7676c  7679c  7693cm  7704cm  7
711cm  7722c  7726c  7729cm  7733c  7738c  7749c  7759cm  7761c  7762c  7763c  7764cm  7770cm  7775cm  7777cm  7778c  7792cm  7797cm  7798cm  7799c  7800cm  7803cm
 7807cm  7808cm  7809cm  7849cm  7866cm  7867cm  7870cm  7886c  7899c  7905cm  7934c  7989cm  8024c  8033cm  8056cm  8199cm  8209c  8246cm  8319cm  8477c  8487cm  8
500c 40805c

复制上面所有数据列，将其中的m,c等去掉，只保留干净的pid集合，然后统一kill掉。

[root@itranCentOS /]# kill -9 7243
[root@itranCentOS /]# kill -9 7261
[root@itranCentOS /]# kill -9 7265
[root@itranCentOS /]# kill -9 7294
[root@itranCentOS /]# kill -9 7386
[root@itranCentOS /]# kill -9 7418

kill掉之后卸载home

[root@itranCentOS /]# fuser -m /home/
[root@itranCentOS /]# umount /home

#删除/home所在的lv

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

扩容/dev/mapper/cl_itrancentos-root

[root@itranCentOS /]# lvextend -L +1024G /dev/mapper/cl_itrancentos-root
  Size of logical volume cl_itrancentos/root changed from 70.00 GiB (17920 extents) to <1.07 TiB (280064 extents).
  Logical volume cl_itrancentos/root successfully resized.
[root@itranCentOS disk]# lvextend -L +258G /dev/mapper/cl_itrancentos-root
  Size of logical volume cl_itrancentos/root changed from <1.07 TiB (280064 extents) to 1.32 TiB (346112 extents).
  Logical volume cl_itrancentos/root successfully resized.

扩展/dev/mapper/cl_itrancentos-root文件系统

[root@itranCentOS /]# xfs_growfs /dev/mapper/cl_itrancentos-root
meta-data=/dev/mapper/cl_itrancentos-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 286785536
[root@itranCentOS /]# df -h
文件系统                         容量  已用  可用 已用% 挂载点
devtmpfs                          28G     0   28G    0% /dev
tmpfs                             28G     0   28G    0% /dev/shm
tmpfs                             28G   18M   28G    1% /run
tmpfs                             28G     0   28G    0% /sys/fs/cgroup
/dev/mapper/cl_itrancentos-root  1.1T   13G  1.1T    2% /
/dev/sda2                       1014M  238M  777M   24% /boot
/dev/sda1                        599M  7.3M  592M    2% /boot/efi
tmpfs                            5.5G   16K  5.5G    1% /run/user/42

重新创建home

重新创建home LV【cl是VG Name，据实际情况而定】

[root@itranCentOS disk]# lvcreate -L 500G -n home cl_itrancentos
  Logical volume "home" created.

创建文件系统

[root@itranCentOS disk]#  mkfs.xfs /dev/mapper/cl_itrancentos-home
meta-data=/dev/mapper/cl_itrancentos-home isize=512    agcount=4, agsize=32768000 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1
data     =                       bsize=4096   blocks=131072000, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=64000, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

重新挂载home

[root@itranCentOS disk]# mount /dev/mapper/cl_itrancentos-home /home/
[root@itranCentOS disk]# df -h
文件系统                         容量  已用  可用 已用% 挂载点
devtmpfs                          28G     0   28G    0% /dev
tmpfs                             28G     0   28G    0% /dev/shm
tmpfs                             28G   18M   28G    1% /run
tmpfs                             28G     0   28G    0% /sys/fs/cgroup
/dev/mapper/cl_itrancentos-root  1.1T   13G  1.1T    2% /
/dev/sda2                       1014M  238M  777M   24% /boot
/dev/sda1                        599M  7.3M  592M    2% /boot/efi
tmpfs                            5.5G   16K  5.5G    1% /run/user/42
/dev/mapper/cl_itrancentos-home  500G  3.6G  497G    1% /home

至此，扩容已完成。手痒的话，动动手尝试一下。