Partitioning for Xen/KVM server during deployment CentOS 7 node

The guide describes the steps for manual partition during the deployment of CentOS 7 server with a single 100G HDD

Note: The instruction is for the deployment from CentOS 7 ISO image

Prerequisites: server with mounted CentOS ISO image, 100G HDD

1. Launch Installation Wizard. Choose the language and click Continue
   
   
2. On the next page select INSTALLATION DESTINATION
   
   
3. Select I will configure partitioning option and Done
   
   
4. On the next page choose LVM and click on "+"
   
5. Add '/boot', 'swap'  and '/' partitions, after that click on Done. 33.99GiB in that case is amount of unallocated free disc space
   
   
   
6. Confirm partitioning scheme by clicking on Accept Changes
   
7. Click on Begin Installation button
8. Set ROOT PASSWORD and proceed with installation

The next step is create a physical device for unallocated free disk space and create a volume group

1. Connect to the server via SSH or VNC
2. Check the current partitioning:

   # lsblk
   NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
   sda 8:0 0 100G 0 disk
   Б■°Б■─sda1 8:1 0 2G 0 part /boot
   Б■■Б■─sda2 8:2 0 64G 0 part
   Б■°Б■─centos-root 253:0 0 60G 0 lvm /
   Б■■Б■─centos-swap 253:1 0 4G 0 lvm [SWAP]
   sr0 11:0 1 792M 0 rom 

3. Create a new device for unallocated free disk space using fdisk command. Example of such procedure is below:

   # fdisk /dev/sda
   Welcome to fdisk (util-linux 2.23.2).
   
   Changes will remain in memory only, until you decide to write them. Be careful before using the write command.
   
   Command (m for help): n
   Partition type:
   p primary (2 primary, 0 extended, 2 free)
   e extended
   Select (default p): p
   Partition number (3,4, default 3): 3
   First sector (138430464-209715199, default 138430464): 138430464
   Last sector, +sectors or +size{K,M,G} (138430464-209715199, default 209715199): 209715199
   Partition 3 of type Linux and of size 34 GiB is set
   
   Command (m for help): t
   Partition number (1-3, default 3): 3
   
   Hex code (type L to list all codes): 8e
   Changed type of partition 'Linux' to 'Linux LVM'
   
   Command (m for help): wq
   The partition table has been altered!
   
   Calling ioctl() to re-read partition table.
   
   WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
   The kernel still uses the old table. The new table will be used at
   the next reboot or after you run partprobe(8) or kpartx(8)
   Syncing disks.
   # partprobe /dev/sda
   # lsblk
   NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
   sda 8:0 0 100G 0 disk
   Б■°Б■─sda1 8:1 0 2G 0 part /boot
   Б■°Б■─sda2 8:2 0 64G 0 part
   Б■┌ Б■°Б■─centos-root 253:0 0 60G 0 lvm /
   Б■┌ Б■■Б■─centos-swap 253:1 0 4G 0 lvm [SWAP]
   Б■■Б■─sda3 8:3 0 34G 0 part
   sr0 11:0 1 792M 0 rom

4. After that create a volume group for the new device /dev/sda3

   # pvcreate /dev/sda3
   Physical volume "/dev/sda3" successfully created.
   # vgcreate -s 32M solusvm /dev/sda3
   Volume group "solusvm" successfully created
   # vgs
   VG #PV #LV #SN Attr VSize VFree
   centos 1 2 0 wz--n- 64.00g 4.00m
   solusvm 1 0 0 wz--n- <33.97g <33.97g

   The new volume group solusvm has been created that will be used as LVM storage for KVM/Xen VPSes

At the current point partitioning part has been complete and the server is ready for SolusVM installation