Steps to Optimize Network Quality of Service in Your Data Center

Virtualization technologies have evolved such that support for multiple networks on a single host is a must-have feature. For example, Red Hat Enterprise Virtualization allows administrators to configure multiple NICs using bonding for several networks to allow high throughput or high availability. In this configuration, different networks can be used for connecting virtual machines (using layer 2 Linux bridges) or for other uses such as host storage access (iSCSI, NFS), migration, display (SPICE, VNC), or for virtual machine management.  While it is possible to consolidate all of these networks into a single network, separating them into multiple networks enables simplified management, improved security, and an easier way to track errors and/or downtime.

The aforementioned configuration works great but leaves us with a network bottleneck at the host level. All networks compete on the same queue in the NIC / in a bonded configuration and Linux will only enforce a trivial quality of service queuing algorithm, namely: pfifo_fast, which queues side by side, where packets can be enqueued based on their Type of Service bits or assigned priority. One can easily imagine a case where a single network is hogging the outgoing link (e.g. during a migration storm where many virtual machines are being migrated out from the host simultaneously or when there is an attacker VM). The consequences of such cases can include things like lost connectivity to the management engine or lost storage for the host.

A simple solution is to configure

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Top 5 Skills Virtualization Admins Must Have to Stay Relevant in 2016

In the past few years, virtualization admins have been hailed as heroes for enabling their organizations to significantly slash costs while improving service levels to the lines of business. Since the IT industry is constantly evolving, how can virtualization admins position themselves for success and avoid being rubber ducks in 2016? Below, we will look at 5 skills that should be in your toolkit in order to remain relevant in your organization.

1. Develop a deep understanding of how DevOps fits into your organization

According to Gartner, “By 2016, DevOps will evolve from a niche strategy employed by large cloud providers to a mainstream strategy employed by 25 percent of Global 2000 organizations.” Like many people, you might be asking yourself – what exactly does DevOps mean? DevOps is

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