RHEV 3.1 – an overview about the new features
RHEV-M
Recently Red Hat announced the public availability of RHEV 3.1.
Finally, no more Windows needed for the whole software stack 
In 3.0, the new webadmin interface was already inncluded, as a tech preview and had its problems. Now with 3.1 its working great and looks neat. In contrary to 3.0, it is now listening on the standard ports 80 and 443. This will probably help users in organizations with strict proxy policies and setting.
So what else is new?
The supported number of virtual CPUs in a guest is now ridiculous 160, and RAM per guest is at ridiculous two Terabytes. But this are the least import updates.
Especially on the storage side, a lot of effort has been done and long missing features integrated.
From my point of view, the most important new feature is the possibility to have disks from more than one Storage Domain attached to a virtual machine. This would allow to install the Operating system to cheap SATA storage while data disks are super fast SSDs.
There is also support for live snapshots, but snapshots are (as on other platforms) kind of problematic because they are COW (Copy-On-Write). This can lead to I/O performance problems. Snapshots are a cool feature for i.e. taking a snapshot before updating software etc. Be sure you remove the snapshot afterwards if you want to keep a good I/O performance.
You now can use DirectLUN directly from the GUI without the usage of hooks. DirectLUN allows to attach FibreChannel and iSCSI LUNs directly to a Virtual Machine. This is great when you want to use shared filesystems such as GFS.
Another nice feature is Live Storage Migration which is a technical preview, means: Unsupported for the moment. It probably will be supported in a later version. Storage live migration is a nice feature when you need to free up some space on a storage domain and you can not shut down a VM. Be sure to power-cycle the VM in question as soon as your SLA allows it, to get rid of the Snapshot (COW here again).
If you want to script stuff or you are too lazy to open a brower, there is now a CLI available. Have a look to the documentation.
If you want to integrate RHEV deeper into your existing infrastructure, such as RHN Satellite, Cobbler, Your-super-duper-CMDB or IaaS/PaaS broker, there are two different APIs available. For the XML lovers, there is the previously known RestAPI which has some performance improvements. For the XML haters, there is now a native Python API which allows to to access RHEV entities directly as objects in your Python code. For both APIs, have a look to the Documentation.
I personally like the Python API, because a lot of other Red Hat infrastructure products come with Python APIs. So it is very easy to integrate those software pieces.
Under the hood, it is now powered by JBoss EAP6 instead of version 5. To be able to connect to standard ports 80 and 443, there is an Apache httpd with mod_proxy_ajp.