In-Depth
A Trio of Technologies for Tackling Expansions in the Data Center
When used together, server virtualization with N-Port ID Virtualization (NPIV), blade servers, and Fibre Channel SANs provide a mature, robust infrastructure for data centers.
By Jim Walery
The growth of blade server virtualization has resulted from data centers' need for increasingly flexible and efficient information technology to handle the current and expected expansion of applications, data and servers. Fibre Channel Storage Area Network (SAN) solutions work with blade servers and eliminate issues associated with increasing amounts of data, thereby enhancing the server's overall power efficiency, ease of deployment, and manageability. We will explain how, when used together, the technologies of server virtualization with N-Port ID Virtualization (NPIV), blade servers, and Fibre Channel SANs provide a mature, robust infrastructure for data centers in today's technology climate.
Components and Benefits
Server virtualization enables the deployment of several full-featured application environments called "virtual machines" (VMs) or "guests" on a single (or a few) servers. Hardware resource scheduling and management is run behind the scenes by a "hypervisor": a user-invisible operating system. Server virtualization delivers the following benefits to data centers:
- Lower power and cooling costs thanks to the consolidation of multiple lightly used servers into a single, efficiently used server
- Reduced management and maintenance overhead, in direct relation to the reduced number of servers, freeing IT staff for other tasks
- Faster provisioning for new applications, which only requires setting up a new VM using available server, network, and storage resources
- Improved disaster recovery capability, as the VMs can be moved quickly and restarted faster and more reliably on alternate servers
Blade servers are self-contained, high-density computer servers. Many traditional server components for storage, power and cooling have been removed or redesigned so they can be shared among servers. Blade server benefits include lower power and cooling costs (further reducing square footage costs or delaying data center expansion), easier server provisioning (because servers are located in a central area), and simplified server cabling than used with standard servers.
Fibre Channel SANs are external storage networks connected with Fibre Channel. Fibre Channel SANs offer the highest transfer speeds with the greatest reliability. The scalable bandwidth from Fibre Channel SANs serves the combined I/O of the multiple hosted applications, with headroom for growing or migrated workloads. These SANs offer several options for redundancy and failover and can efficiently handle a large amount of data. Thanks to the technology's maturity and strong vendor support, Fibre Channel SANs are the market leader in external storage.
NPIV is a standard for Fibre Channel Host Bus Adapters (HBAs) and Fibre Channel over Ethernet (FCoE) Converged Network Adapters (CNAs), allowing each VM specialized access to only its required storage resources using unique fabric addresses. NPIV technology provides:
- Standard storage management methodology across standard (blade or non-blade) and virtual servers
- Portability of access privileges during VM migration
- Fabric performance, as NPIV provides quality of service (QoS) and prioritization for ensured VM-level bandwidth assignment
- Auditable data security due to zoning (one server, one zone)
Figure 1 shows multiple VMs located on a blade server with an HBA connected to a switch, which is then connected to a Fibre Channel SAN. NPIV is used in the HBA and switch, ensuring that the VM is connected to the correct storage device.
NPIV must be supported in the HBA or CNA, the switch, and the hypervisors. NPIV is a standard describing how a single Fibre Channel HBA port can register with the fabric using several worldwide port names (WWPNs). Using multiple addresses through a single adapter port is valuable in virtual servers because it enables zoning and Logic Unit Number (LUN)-masking, giving each VM specialized access to only its required storage resources.
In addition, exclusive assignment of buffer resources to priority VMs, through their "port," provides added granularity to fulfill service level agreements (SLAs). Finally, the ability to "tear down" a virtual port and reinitiate it on a different server greatly enhances VM capabilities for load-balancing, portability, and incident recovery. In short, NPIV enhances SAN connectivity, flexibility, resource allocation and recovery, enabling new classes of applications, fuller data center integration, and accelerated virtual server deployment.
Advantages of Combined Technologies
Combining server virtualization, blade servers, Fibre Channel SANs, and NPIV technologies allows for greater data center consolidation, flexibility, and efficiency. Data center managers are now realizing the benefits of physical consolidation (via blade servers) and logical consolidation (via server virtualization).
Blade servers and virtualization draw on enterprise storage resources and require the capabilities of NPIV to maintain SAN best practices. The portability and recovery capabilities of virtual environments rely on external shared storage. In addition, the high performance delivered by the Fibre Channel protocol is best positioned to serve the higher I/O requirements for multiple VMs running on a single server.
SAN connectivity helps enable the benefits of server virtualization; server virtualization drives an increased need for SAN connectivity. Recent improvements include:
- Specialized blade servers for virtualization, which include more memory, increased CPU performance, and networking capabilities, allowing each blade server to host more VMs
- Specialized blade servers that include preloaded hypervisors, so virtualization is delivered "out of the box"
- Blade server management software, which can manage physical and virtual machines at the same time from a single interface
- Easier blade server replacement and reconfiguration, as the new blade server can assume the identity of the replaced blade server by using the capabilities of the virtual environments and blade server utilities
Virtual server technology can move workloads easily across VMs on a single server; however, it becomes a challenge when moving VMs from one physical machine to another because changes to the LAN and SAN are required. By pooling and sharing multiple network connections across multiple servers and VMs, blade server software tools extend portability by allowing physical setup and movement transparently from the LAN and SAN. By combining VM and virtual SAN technology to create a pool of resources to simplify the server connections to the network and storage, a blade server becomes an end-to-end adaptive infrastructure out of the box.
Blade servers have become the platform of choice for organizations that are using server virtualization; these organizations are now more likely to be implementing blade servers than standard servers.
NPIV complements infrastructure consolidation by removing security and performance management obstacles and opening up powerful configuration and optimization capabilities. NPIV is recommended for use with mission-critical VMs but is optional for file and print server VMs, which may not require the manageability NPIV affords.
Summary
Combining the technologies of server virtualization, blade servers, NPIV, and Fibre Channel SANs offers data center managers the ability to dramatically increase server utilization, improve infrastructure resiliency, and roll out new servers (virtual or physical) more quickly. All of these technologies are mature and continue to be enhanced so they work together more seamlessly.
Additionally, these combined technologies can lower power and cooling costs, carbon emissions, and administrative costs by using fewer physical servers. Combining these technologies provides data center mangers with the mature, flexible, robust, and reliable infrastructure they require.
Jim Walery is a senior product marketing manager at Emulex Corporation. You can reach the author at jim.walery@emulex.com.