XenServer 6.2 was orginally released in June of 2013. It was the first release of XenServer as part of the open source initiative. While XenServer 6.2 remains a supported platform by Citrix, existing users are encouraged upgrade to XenServer 6.5 at their earliest convenience. New installations should be made using XenServer 6.5.
XenServer 6.5 introduces many architectural improvements which aim to improve overall performance and removes a number of scalability limitations in XenServer 6.2.
64-bit Control Domain Linux Kernel
The new 64-bit Control Domain (Dom0) enables XenServer to accommodate many more PCI devices per host (NICs, GPUs, and so on), and allows the use of devices that are 64-bit only (including many Solid State Drive solutions).
New Xen Project Hypervisor v4.4
XenServer 6.5 includes the latest Xen Project hypervisor available; v4.4 delivers many improvements. It vastly increases the number of virtual event channels available for Domo, from 1023 to 131071, which translates into a correspondingly larger number of attached virtual devices.
Re-introduction and Improvements to Workload Balancing
XenServer 6.5 sees the return of the WorkLoad Balancing (WLB) virtual appliance. WLB gives system administrators deep insight into system performance, allowing infrastructure optimization.
Distribute Virtual Switch Controller – new version included and deprecation rescinded
The Distributed Virtual Switch Controller (DVSC) is fully supported within XenServer 6.5 and the deprecation notice issued at 6.2 is rescinded.
Newly Supported Guests
- Support is added for the following new guests:
SLES 11 SP3 and SLES 12
CentOS 5.10, 5.11, 6.5, and 7.0
RedHat 5.10, 5.11, 6.5, and 7.0
Oracle Linux 5.10, 5.11, 6.5, and 7.0
Oracle UEK 6.x