data center

The philosophy of clustering vs HA

IBM’s Massimo Re Ferre’ with another long thought-piece on the philosophical differences between traditional custering (application- and OS-dependent, complicated) with approaches like VI3’s High Availability (HA) (treats workload as a virtual appliance, simpler). Massimo works directly with customers, so although he recognizes that paradigms are changing, he looks at the strength and weaknesses of both approaches, and alludes some of the organizational and operational changes you’ll have to make to get there.

Link: IT 2.0 Main Blog : VMware HA Vs Microsoft Cluster Server: we are at the inflection point.

If you stop for a minute and think about what it is happening in this
x86 virtualization industry, you’ll notice that many infrastructure
services that were typically loaded within the standard Windows OS are
now being provided at the virtual infrastructure layer. An easy example
would be network interface fault tolerance: nowadays in virtual
environments you typically configure a virtual switch at the
hypervisor level, comprised of a bond of two or more Ethernet adapters
and you associate virtual machines to the switch with a single virtual
network connection. What you have done in this case is that you have
basically delegated the virtual infrastructure of dealing with Ethernet
connectivity problems. This is a very basic example and there are many
others like this such as storage configuration/ redundancy/ connectivity.  …

We are clearly at an inflection point now where many customers that
used to do standard cluster deployments on physical servers (which was
the only option to provide high availability) are now arguing how to do
that. They now have the choice to either continue to do so in virtual
servers as opposed to physical servers (thus applying the same rules,
practices and with little disruption as far their IT organization
policies are concerned) or turning to a brand new strategy to provide
the same (or similar) high availability scenarios (at the cost of
heavily changing the established rules and standards). The reason I am
saying we are at an inflection point is because I really believe that
the second scenario is the future of x86 application deployments, but
obviously as we stand today there are things that you cannot
technically do or achieve with it. Plus, there is a cultural problem
from moving from an established scenario to the other.


0 comments have been added so far

  1. Our University is in the process of moving many of our traditional clustered apps into a VM environment. Our answer is to transition a portion of the clusters to VM and then slow move the entire cluster in over time. The options with VMWare over NFS really make this system look nice.

Leave a Reply

Your email address will not be published. Required fields are marked *