1. Installing Oracle Linux
  2. Installing a System With a Btrfs root File System

6 Installing a System With a Btrfs root File System

Oracle Linux uses XFS as the default file system, but it also supports other file systems such as ext2, ext4, and so on.

The Btrfs file system is supported in Oracle Linux, but only on UEK. Thus, to install Oracle Linux with Btrfs, you must use the UEK ISO image.

For more information about file systems in Oracle Linux, see Oracle Linux 9: Managing Local File Systems.

Like any installation of a standard Oracle Linux release, installing the OS with a Btrfs file system can also be completed in two modes:

You can also install a system with a Btrfs root file system using kickstart automation as described in Automating the Installation by Using Kickstart. If you choose to perform an automated installation and you create your own network installation setup, as described in Creating a Network Installation Setup, make sure that you configure your network boot to use the installation kernel and ram-disk image provided on the UEK ISO image and that you have mirrored all of the required repositories, or you may get an error stating that Btrfs is not supported for your partitioning type.

Using the GUI Installer

The following steps are limited to what is relevant to a Btrfs installation. For the complete procedure, refer to Installing in Graphics Mode.

  1. Boot the system from the installation media using the Unbreakable Enterprise Kernel boot ISO file.

  2. On the Installation Summary screen, select Installation Destination, then select the local disks and add any Specialized & Network disks that you want to use for the installation.

  3. Under Storage Configuration, select Custom and then click Done.

    The Manual Partitioning screen is displayed. Custom partitioning can be either automatic, where mount points are automatically created, or manual, where you individually create and configure mount points.

    Automatic Partitioning

    1. From the drop-down list of partitioning schemes, select Btrfs.

    2. Click Click here to create them automatically.

      The following mount points are created:

      • /home

      • /boot

      • / (root)

      • swap

    3. Optionally, select each mount point and verify in the corresponding information that the mount point's device type is Btrfs.

      Note:

      The swap partition cannot be configured as a Btrfs file system.

      The mount point information should resemble the following example:

      Figure 6-1 Mount Points


      The image shows the mount points that are created for Btrfs. The mount points are listed on the left. The root (/) mount point is highlighted and there are options on the right that show the mount point's current configuration.

    4. Optionally for each mount point, configure the respective volumes.

    5. Click Done, then on the partition summary that is displayed, click Accept Changes.

    Manual Partitioning

    1. From the drop-down list of partitioning schemes, select Btrfs.

    2. Click + to create the mount point.

      The Add A New Mount Point window opens.

    3. Select the mount point and enter its size as prompted, then click Add mount point.

      As a minimum, create mount points for /, /boot, /home, and swap.

    4. Select each mount point you created and verify that their corresponding information is correct.

      Note:

      The swap partition cannot be configured as a Btrfs file system.

    5. Optionally, modify the volume of each mount point, as needed.

    6. Click Done and on the partition summary that is displayed, click Accept Changes.

  4. Complete the configuration of any additional sections in the Installation Summary screen.

  5. Click Begin Installation.

Using the Text Installer

The following steps are limited to what is relevant to a Btrfs installation. For the complete procedure, refer to Installing in Text Mode.

  1. From the text based installation menu, type 5 to configure Installation Destination.

    1. Installation Destination: If your preferred disk is already selected, type c to continue. Otherwise, type the number corresponding to the disk you want to use, press Enter, then type c to continue.

    2. Partitioning Options: If your preferred option is already selected, type c to continue. Otherwise, type the number corresponding to your preferred option, press Enter, then type c to continue.

    3. Partition Scheme Options: Type 2 to use Btrfs, press Enter, then type c to return to the main menu.

  2. Configure all the remaining settings that are flagged with the warning symbol (!).

  3. After you have completed configuring all the installation options, type b to begin the installation.

Verifying the Btrfs Installation

When the entire installation process has completed and you can log in to the system, you can use different tools to verify the file system configuration. The following example shows the output of the sudo df -Thk command: 

sudo df -Thk
Filesystem Type  1K-blocks    Used Available Use% Mounted on
...
/dev/sda2  btrfs  15097856 4803120  10052400  33% /
/dev/sda2  btrfs  15097856 4803120  10052400  33$ /home
/dev/sda2  btrfs  15097856 4803120  10052400  33$ /boot
...

Optionally, you can complete other tasks as described in Postinstallation Configuration.