Oracle Linux as a replacement for RHEL\CentOS

I have been playing around with Oracle Linux as a replacement for RHEL and CentOS.

Unlike RHEL, updates are available without a support contract.
Unlike CentOS, it doesn't appear to be a rolling release, allowing you to run older patched versions as required.

Useful URLs so far:

Download (You need a free Oracle account):
https://edelivery.oracle.com/linux

Public update sever:
https://public-yum.oracle.com/

How to switch to Oracle Unbreakable Kernel:
https://docs.oracle.com/cd/E37670_01/E51472/html/uek3_install_public_yum.html

How to install VirtualBox guest additions:
https://www.virtualbox.org/manual/ch04.html#idp95340944

How to limit the number of installed Kernels:
http://www.if-not-true-then-false.com/2012/delete-remove-old-kernels-on-fedora-centos-red-hat-rhel/

Anyone know of a way to stop the version upgrading from 7.0 to 7,1 for example?

Fun with file systems

I've identified a need to replicate some file system information in Linux for a number of reasons:

1. Primary to secondary site for DR purposes
2. As above but with file locking for limited live-live operation
3. As above but with record locking for full live-live operation (thinking SAMBA shares here)

I've identified a number of file system features that will let me do this, so I'm going to have a geeky day looking at them:

1. B-tree file system (BTRFS)
2. Logical volume manager (LVM)
3. A. N. Other cluster file system

I think BTRFS is going to be to slow for virtual machines, and LVM has the advantage of running different file systems inside the container sysyem. The might be other options such as rsync but I would really like the solution to be as independent of the applications being replicated as possible (don't want to run rsync in a virtual machine for example).

Any suggestions greatly received, but I'm off to get CentOS in Oracle VM VirtualBox installed for a starting point.