Large Layer 2 Domains and Vmotion

Vmware V-motion requires physical hosts to be in the same layer two domain. This goes against the grain in networks that were built around the principle of reducing the size and reach of broadcast domains.Layer 2 broadcast domains reduces the bandwidth available to our applications due to effect of frame flooding and also because Spanning tree’s operation disables redundant paths in our layer 2 networks.

Vmotion’s layer 2 requirement may be one of major reason why Flat layer 2 networks are being optimized.These optimization’s mitigate against the effects of broadcasts and unknown Unicast flooding which wastes network bandwidth.TRILL which is not really necessary to support Vmotion, has been developed to replace spanning tree in bandwidth intensive use cases that need all links to be forwarding at once. The existence of applications that require huge Flat networks will ensure the continued evolution of the layer 2 switching space and thus augment the simple plug N play nature of Ethernet networks that most people appreciate.

 

 

 

 

 

 

 

 

Enhancing Disaster Recovery Using Virtualization

The ability to convert physical computers and servers to virtual machines is an often an understated benefit of server virtualization. Virtual Servers are essentially flat files stored in a proprietary format.These files can be created periodically and stored on backup media for disaster recovery purposes. Business’s that have have strict recovery times and need greater availability may virtualize their physical servers and have these virtual machines hosted on physical servers located offsite. The Physical servers at the companies main office and The Virtual Servers offsite could be configured to sync with each other while clustered in master and slave setup with the Virtual Machines serving as slaves backing up a their physical masters. If a physical server goes down a Virtual server will be able to handle processing in few seconds. Tools such as Double Take can be used to synchronize the data residing in disparate locations while a WAN circuit is needed to link both locations .