Btrfs and new file system structure agreed for Fedora 17
The members of the Fedora Engineering Steering Committee (FESCo), who decide on the technical development aspects of Fedora, have accepted a range of new features proposed by developers for version 17 of the Linux distribution. As things currently stand, the project plans to make another attempt to switch to using Btrfs as its default file system in this version, scheduled for release in May 2012. Such a move had been discussed for Fedora 16, but was later postponed because the file system didn't meet several criteria essential to allow the switch. For example, an improved tool is needed for checking and repairing Btrfs drives; such a tool continues to be a requirement, and its unavailability may cause Fedora to further postpone the switch.
The list of accepted new features also includes the plan to store all applications and libraries in the /usr/ directory. This means that the /lib/, /lib64/, /bin/ and /sbin/ directories will become obsolete; however, for compatibility reasons, they will be replaced by symbolic links pointing to the appropriate subdirectories in /usr/. These restructuring measures will allow atomic filesystem snapshots to be generated when updating; this will enable users who encounter difficulties to return to an older version without losing any changes that may have been made in /etc/ or /var/. It will also make it easier to integrate /usr/ in read-only form or access a /usr/ share from multiple systems. The usr directory can be stored on a separate drive but must be mounted by initramfs when the system is started. The developers have dropped their original plan to stop differentiating between /usr/bin/ and /usr/sbin/.
With version 17, the Fedora developers also plan to remove ConsoleKit and, at the same time, introduce automatic multi-seat support. It is also planned that all services will start via systemd service units, and that the GNOME shell will be functional on systems without 3D acceleration.