The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
If the root partition is formatted by using
Btrfs, the system is unable to boot into RHCK. This problem
occurs because the features that are included in the version
of Btrfs provided are not supported on older kernel versions.
Note that Btrfs is included onl.y as a technology preview for
RHCK and is not fully supported on this kernel.
However, Btrfs is fully supported in production with the UEK release. Systems that boot into this kernel are unaffected by this particular issue.
When formatting file systems from the installation ISO, be
aware that formatting the root partition
with Btrfs makes it impossible to boot into the RHCK. Note
that btrfs is the default file system for
system disks when using the boot-uek.iso.
If you are installing from this ISO and you intend to use the
RHCK, you must change the default system disk layout in the
installer. (Bug ID 23198167)