OpenShift-Lab/doc/SAMPLE_PARTITIONING.md

Sample partitioning

Three disks partitions

This guide provides step-by-step instructions to help you partition your disks for OpenShift.

It assumes you created a Virtual Machines with three disks :

• /dev/sda: 10 GiB for the Operating System
• /dev/sdb: 30 GiB for the OpenShift PVs
• /dev/sdc: 50 GiB for the Docker Storage

/dev/sda is partitioned during installation. If possible, use LVM that will give you greater flexibility if you need to extend that partition later.

Make sure to NOT allocate swap space since it is a recommended best practice.

After installation, you should have :

• /boot backed by a primary partition, 512 MiB
• / backed by a Volume Group named rhel, with a Physical Volume backed by a primary partition, 9.5 GiB
• /dev/sdb and /dev/sdc are now empty

$ sudo fdisk -l /dev/sda

Disk /dev/sda: 10.7 GB, 10737418240 bytes, 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000a801b

  Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1050624     524288    83  Linux
/dev/sda2         1050625    20971519     9960447   8e  Linux LVM

$ sudo vgs
 VG      #PV #LV #SN Attr   VSize  VFree
 rhel      1   1   0 wz--n-  9.50g     0

$ sudo pvs
 PV         VG      Fmt  Attr PSize  PFree
 /dev/sda2  rhel    lvm2 a--   9.50g     0

You can now partition /dev/sdb (OpenShift Persistent Volumes):

$ sudo fdisk /dev/sdb 
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
   e   extended
Select (default p): p
Partition number (1,2,3,4, default 1): 1
First sector (2048-20971519, default 2048): <ENTER>
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2049-20971519, default 20971519): <ENTER>
Using default value 20971519
Partition 1 of type Linux and of size 30720 MiB is set

Command (m for help): t
Partition number (1, default 1): 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): w
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.

Create a Volume Group and add the new partition:

sudo vgcreate storage /dev/sdb1

Create a new Logical Volume:

sudo lvcreate storage -n openshift -l %FREE

Format it:

sudo mkfs.xfs /dev/mapper/storage-openshift

Create an entry in /etc/fstab:

sudo -i
echo "/dev/mapper/storage-openshift /var/openshift xfs defaults 0 0" >> /etc/fstab

Finalize the setup:

sudo mkdir /var/openshift
sudo mount /var/openshift
sudo chmod 777 -R /var/openshift
sudo chcon -Rt svirt_sandix_file_t /var/openshift

You can now partition /dev/sdc (Docker Storage):

$ sudo fdisk /dev/sdc 
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
   e   extended
Select (default p): p
Partition number (1,2,3,4, default 1): 1
First sector (2048-20971519, default 2048): <ENTER>
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2049-20971519, default 20971519): <ENTER>
Using default value 20971519
Partition 1 of type Linux and of size 51200 MiB is set

Command (m for help): t
Partition number (1, default 1): 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): w
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.

Create a Volume Group and add the new partition:

sudo vgcreate docker /dev/sdc1

And that's it ! :)