During deployment of KVM node all free space is assigned to /home partition

Symptoms 

During deployment of KVM node all free space is assigned to /home partition.

There is no free physical extents (PE) on the volume group. As a result, there is no room for the new virtual server on the volume group:

CONFIG_TEXT: # vgdisplay | grep PE
PE Size 4.00 MiB
Total PE 16127
Alloc PE / Size 16126 / 62.99 GiB
Free PE / Size 0 / 0.00 MiB

Cause

Slave host node has been created with default settings

Resolution

The recommended solution is redeployment of the KVM slave node with manual partitioning.

If this is not possible due to the fact that data center does not support installation using ISO image or there is pre-defined templates, apply the steps below as a workaround.

Warning: The steps below can cause complete malfunctioning of the whole server. Make sure that all necessary data copied to external storage.

1. Log into slave server via SSH
2. Copy all the necessary data from /home partition to external storage. If there is enough disk space on the root partition, you can create a backup directory and move necessary data to it:

   # mkdir /backuphome
   # cp -rp /home/* /backuphome/

3. Un-mount /home partition:

   # umount /home

4. Update /etc/fstab and remove /home mount point, the line like below:

   # cat /etc/fstab | grep home
   /dev/mapper/centos-home /home xfs defaults 0 0

5. Remove corresponding logical volume:

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

   Verify that there free physical extents are available:

   # vgdisplay | grep Free
   Free PE / Size 5123 / 20.01 GiB

6. Restore the content of the /home directory from the backup:

   # cp /backuphome/* /home
   # rm -rf /backuphome