9.14.4. Create a Btrfs subvolume
Fedora 20 includes Btrfs as a technology preview to allow you to experiment with this file system. You should not choose Btrfs for partitions that will contain valuable data or that are essential for the operation of important systems.
Btrfs is a type of file system, but has several features characteristic of a storage device. It is designed to make the file system tolerant of errors, and to facilitate the detection and repair of errors when they occur. It uses checksums to ensure the validity of data and metadata, and maintains snapshots of the file system that can be used for backup or repair.
During manual partitioning, you will create Btrfs subvolumes rather than volumes. The installer then automatically creates a Btrfs volume to contain these subvolumes. The sizes reported for each Btrfs mount point in the left pane of the Manual Partitioning screen will be identical because they reflect the total size of the volume rather than each individual subvolume.
To create a Btrfs subvolume:
Click the Device Type dropdown menu and select BTRFS.
Beneath the File System dropdown menu (which is grayed out for Btrfs), an additional menu will appear: Volume Group. This menu will display a newly-created volume group name, such as fedora00. If this group and its default settings (no RAID level, automatic sizing) are acceptable, skip to step 5.
To edit the group, click
Modify to open the
Configure Volume dialog. Choose a name and select which disks will be included. Optionally, select a RAID level and a Sizing Policy (choose between
Automatic,
As large as possible, and
Fixed, to set the size manually). For information on RAID levels, refer to
Section 9.14.2, “ Create Software RAID ”.
Alternatively, click the dropdown menu and select Create a new volume to add an additional group using the same dialog.
Click Save once the volume is configured.
Only RAID 0 and RAID 1 are available for btrfs subvolumes.
Keeping the partition selected in the left-hand pane, select the configuration button below the pane to open the Configure Mount Point dialog. Select which disks will be included as part of the RAID on the subvolume and click Select.
If fewer disks are included than the specified RAID level needs, a yellow notification bar at the bottom of the screen will inform you that Device reconfiguration failed. Clicking this warning prompts a dialog informing you how many disks are required.
Click Update Settings to save your changes, and either continue with another partition or click Done to return to the Installation Summary Menu.
Placing /boot on a Btrfs subvolume may lead to instability and is not recommended.
