How to group volumes together with LVM

When a huge capacity is allocated to the home directory and you want to combine it with the root volume!

Check the current situation

[root@cmst301 ~]# lvdisplay -C
  LV      VG         Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  lv_home vg_cmst301 -wi-ao---- 197.68g
  lv_root vg_cmst301 -wi-ao----  50.00g
  lv_swap vg_cmst301 -wi-ao----   7.83g

Backup of target directory

[root@cmst301 ~]# cp -rp /home /home_bk

Comment out the following line in fstab

/dev/mapper/vg_cmst301-lv_home /home                   ext4    defaults        1 2

Unmount home directory

`current situation`


[root@cmst301 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_cmst301-lv_root
                       50G  6.0G   41G  13% /
tmpfs                 3.9G     0  3.9G   0% /dev/shm
/dev/sda1             477M   78M  374M  18% /boot
/dev/mapper/vg_cmst301-lv_home
                      195G  416M  185G   1% /home

`Unmount`


[root@cmst301 ~]# umount /home

`Verification`


[root@cmst301 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_cmst301-lv_root
                       50G  5.0G   42G  11% /
tmpfs                 3.9G     0  3.9G   0% /dev/shm
/dev/sda1             477M   78M  374M  18% /boot

Delete logical volume

[root@cmst301 ~]# lvremove /dev/vg_cmst301/lv_home
Do you really want to remove active logical volume lv_home? [y/n]: y
  Logical volume "lv_home" successfully removed

Logical volume expansion

[root@cmst301 ~]# lvextend -L +200G /dev/mapper/vg_cmst301-lv_root
  Size of logical volume vg_cmst301/lv_root changed from 247.49 GiB (63357 extents) to 247.59 GiB (63382 extents).
  Logical volume lv_root successfully resized.

File system extension

[root@cmst301 ~]# resize2fs /dev/mapper/vg_cmst301-lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_cmst301-lv_root is mounted on /; on-line resizing required
old desc_blocks = 4, new_desc_blocks = 16
Performing an on-line resize of /dev/mapper/vg_cmst301-lv_root to 64903168 (4k) blocks.
The filesystem on /dev/mapper/vg_cmst301-lv_root is now 64903168 blocks long.

Check the expansion result

[root@cmst301 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_cmst301-lv_root
                      244G  5.0G  227G   3% /
tmpfs                 3.9G     0  3.9G   0% /dev/shm
/dev/sda1             477M   78M  374M  18% /boot