W h i t e p a p e r Why Use 16Gb Fibre Channel with Windows Server 2012 Deployments
Introduction Windows Server 2012 Hyper-V Storage Networking Microsoft s Windows Server 2012 platform is designed for the evolving data center that is experiencing architectural shifts from embryonic to pervasive deployment of virtualization, concurrently with the introduction multi-tenant private and public cloud infrastructures. Supporting this evolution, Windows Server 2012 is engineered to deliver multiple new features for Hyper-V workload virtualization, storage and data networking, all sharing several core attributes, including: n Scalability n Elasticity n Availability n Shared Resources This paper focuses on advanced Fibre Channel (FC) storage and virtualization capabilities in Windows Server 2012, primarily from server FC Host Bus Adapter (HBA) and secondarily from an FC Storage Area Network (SAN) perspectives. A brief review of the key advances in workload virtualization scalability helps establish a context for this discussion. Hyper-V, characterized by Microsoft as massive scale in the box (Jeff Woolsey Microsoft, TechEd North America 2012) now supports up to 320 logical processors on hardware, with 4 TB of physical memory, and 64 virtual processors, and up to 1 TB of memory on a virtual machine (VM). The table below compares Windows Server 2012 to Windows Server 2008 R2 in terms of scalability. Hyper-V Attributes Windows Server 2012 Windows Server 2008 R2 Logical Processors (LP) 320 LPs 64 LPs Physical Memory (in Terabytes) 4 TB 1 TB Virtual Processors (VP) 64 VP 4 VPs Memory per Virtual Machine 1 TB 64 GB Table 1 Windows Server 2012 attributes comparison. Quite simply, this enables virtualization of workloads previously considered non-virtualizable; in addition to increasing virtualization densities in host servers. This level of virtualization capability coupled with increased storage I/O was recently demonstrated by Microsoft during the TechEd EMEA 2012 keynote presentation showing performance of over 1,000,000 IOPS from a single VM. Significant hardware inflection points subsequent to the release of Windows Server 2008 R2, including Intel s Xeon E5 (Romley) multi-core processor, solid-state and cached solid-state storage arrays, 10GbE data networking and 16Gb FC (16GFC) storage networking are collectively providing the necessary hardware ecosystem to take the full advantage of Windows Server 2012. 2
Enterprise Class Storage with Fibre Channel Fibre Channel remains the dominant block storage architecture for large enterprise data centers. One of the characteristics of enterprise data centers is the pervasive deployment of FC Host Bus Adapters (HBAs) and FC Storage Area Networks (SANs) connected to back-end storage arrays. A dedicated network to provide access to block level storage, SANs deliver the benefit of better disk utilization via shared storage, across multiple servers on a resilient, low latency and high throughput storage infrastructure. A VM can be deployed on any physical server that has a connection to the SAN, rather than requiring its storage to be physically connected to its host server. Additional benefits include rapid migration of VMs across this shared storage, migration of storage across servers, as well as enabling diskless servers booting off the SAN, allowing rapid, non-disruptive replacement of server hardware. SANs inherently allow elastic capacity growth as dictated by storage demand. FC SANs thus deliver on the scalability, availability and resource sharing attributes, the overarching themes of Windows Server 2012. On the host server, the latest generation of FC HBAs, some such as the Emulex LightPulse LPe16000, which are Windows Server 2012 Certified, with drivers in-box, enable server-to-storage connectivity at 16Gb Fibre Channel (16GFC), providing the high level of storage I/O performance briefly discussed above. A deeper discussion of the performance benefits of 16GFC is included at the end of this paper. Next we will discuss virtualization technology available with a FC HBA and FC networking fabric for Windows Server 2012 Hyper-V. NPIV FC HBA Virtualization N_Port ID virtualization (NPIV) is an ANSI T11 standard, co-developed by Emulex and IBM, describing how a single FC HBA port, with a single physical N_Port worldwide port name (WWPN) can register with the fabric using several virtual (logical) N_Port WWPNs. The HBA first logs into the SAN fabric (FLOGI), then requests as many fabric IDs from the switch as it has logical ports, identified by unique worldwide port names (WWPN). The fabric will then route messages, display topologies, monitor status for these virtual end points as it already does for the physical ones. The use of multiple addresses through a single physical HBA port is very valuable in Hyper-V servers as it enables zoning and LUN masking, giving each VM specialized access to only its required storage resources. Finally, the ability to tear down a virtual port and reinitiate it on a different Hyper-V host server greatly enhances VM portability for load balancing, agility and incident recovery. In summary, N_Port ID Virtualization enhances SAN connectivity, flexibility, resource allocation and recovery. NPIV requires two capabilities: n The FC HBA and the proximate switch must be able to negotiate several addresses. This is specified as part of the ANSI T11 FC standards, and is available on the latest fabric switches. n The FC HBA driver must be able to accept requests from the operating system to create, modify, delete FC addresses, and provide status on each address. As mentioned earlier, Emulex s FC HBAs have drivers in-box for Windows Server 2012 supporting NPIV. In addition, Emulex OneCommand Manager provides comprehensive administration of NPIV virtual ports. Figure 1 is a simplified representation of an FC HBA with NPIV in a Hyper-V host. 3
Figure 1 FC HBA with NPIV enabled. FC Innovation in Windows Server 2012 Hyper-V Windows Server 2012 delivers several innovative FC related capabilities that underscore the continuing importance of FC architecture in virtualized and cloud-ready data centers. These include: Virtual Fibre Channel Virtual FC extends Fibre Channel functionality to VMs enabling native SAN access directly from the VMs. This is accomplished by providing virtual FC ports within the guest operating system. Using Virtual FC, also known as Synthetic FC, Hyper-V now enables virtualization of workloads that require direct access to SAN storage Logical Unit Numbers (LUNs). Virtual FC for Hyper-V guests uses the previously discussed NPIV T11 standard to map multiple virtual WWPNs to a single physical WWPN. A new virtual NPIV port is created on the host each time a virtual HBA configured VM is started. When the VM stops running on the host, the virtual port is removed. A total of four Virtual FC ports can be configured on each VM. FC HBA ports used for Virtual FC should be set up in a Fibre Channel topology that supports NPIV, and the FC switch should support NPIV ports. 1 http://opennetsummit.org 4
The in-box Emulex LightPulse LPe12000 8GFC and LPe16000 16GFC families of FC adapters, plus OneCommand Manager, support this new Virtual FC functionality and are ready to deliver all the benefits associated with Virtual FC which include: n Hardware cost optimization through VM consolidation Workloads such as SQL Server that require direct access to an FC SAN can now be migrated to virtualized/cloud environments delivering the cost benefits associated with VM consolidation. n Maintaining storage best practices As a corollary to #1, a virtual FC SAN can be created and virtual FC ports connected to it for traditional best practices such as FC zoning. n Optimizing SAN hardware utilization Midrange and high-end storage arrays include functionality enabling selected management tasks to be offloaded from the host server. For example, a LUN snapshot can be taken directly on the SAN hardware using a hardware Volume Shadow Copy Service (VSS) provider from within the VM. n Enabling MPIO High availability & load balancing multipath I/O (MPIO) is now available for a VM as it has been for a non-virtualized workload. The hardware HBA ports are configured for traditional MPIO connectivity to the storage LUNs. Multiple virtual FC HBAs are similarly connected to the LUNs using a separate copy of MPIO running inside the VM. This configuration coexists with the host setup. n High Availability Failover Clustering The guest OS running a VM can now be clustered, using virtual FC and running the Failover Clustering feature, increasing high availability for virtualized workloads, providing protection against application and service failure. Note: Virtual FC does not support Boot from SAN. Live migration Although live migration is also a feature enabled with virtual ports, its importance merits a separate discussion from the list above. One core tenet of Live Migration in Windows Server 2012 Hyper-V is Live migration should just work no tradeoffs (Jeff Woolsey, Microsoft, at TechEd North America 2012). Live migration of a VM across Hyper-V hosts while maintaining FC connectivity is now enabled using virtual FC ports. n A VM is configured two virtual FC ports and two WWPNs, WWPNA & WWPNB n Live migration creates a new instance of the VM on the destination host. This is connected to the FC fabric using WWPNB. Connectivity to the fabric is verified for this instance. n The live migration is completed (memory copy etc.) and the source VM paused and logged out of the fabric. Windows Offloaded Data Transfer (ODX) ODX works as a complementary feature on FC SANs. This new capability increases the value of FC technology, when deployed on compatible storage arrays. ODX enables direct data transfers within or between compatible storage devices without first transferring the data to the host server, instead using token passing between the storage array and the VM. Enabling ODX functionality on a compatible storage array requires assigning of ODX-capable FC LUNs to the VM s virtual FC HBA. 5
The Value of 16GFC for Windows Server 2012 Microsoft has made significant investments in increasing the value of FC technology for the Windows Server 2012 platform. The launch of Windows Server 2012 coincides with the recent 2011 launch of 16GFC, the latest version of FC technology. The scale up enhancements of Windows Server 2012 and Hyper-V along with improvements in agility and availability, in conjunction with the processor and storage hardware inflection points discussed above collectively provide a plethora of reasons to deploy 16GFC. These include: n Doubled throughput, higher IOPS 16GFC delivers 3200 MB/sec bi-directional throughput (double 8GFC s 1600 MB/ sec) and over 1 Million IOPS - supporting deployments of densely virtualized servers, increased scalability and matching the performance of multi-core processors and SSD based storage infrastructure. n Seamless integration 16GFC is backward compatible with 8/4GFC and will auto-negotiate down to the lower speeds. This allows 16GFC devices and switches to be seamlessly integrated into expansion segments of existing FC networks without a forklift upgrade. Equally importantly, existing 8/4GFC OM1-OM4 optic cabling infrastructure can carry 16GFC traffic, further simplifying integration of new and legacy hardware. n Reduced capital expenses (CAPEX) Higher speed 16GFC reduces the number of HBAs and switch ports required to achieve similar performance, resulting in lower front-end CAPEX. Fewer links also mean less structured cabling investment, running at hundreds of dollars per port. n Reduced operating expenses (OPEX) A 16GFC HBA delivers 100% more bandwidth for about a 40% increase in power consumption. Installing 2 8GFC HBAs for doubling bandwidth would result in 100% increase in power consumption while installing a 16GFC HBA can deliver the same result for a 40% increase in power. Reduced power per bit transferred reduces OPEX. Reduced port counts also simplify manageability, improving IT productivity and reduction in associated OPEX. Conclusion Windows Server 2012 adds significant new and enhanced capabilities, engineering an enterprise class and cloud-ready platform, delivering value on multiple attributes including: n Scalability n Elasticity n Availability n Shared Resources Recognizing the importance of Fibre Channel architecture, Microsoft has invested in innovative features and enhancements to preserve the value of the existing infrastructure investments and provide an impetus for expanded deployments of this virtualization-friendly storage networking technology. Virtual Fibre Channel, a key component of this innovation provides multiple benefits for the virtualized data center, along with Windows Offload Data Transfer which delivers complementary benefits for a Fibre Channel SAN. The latest version of Fibre Channel, 16GFC, provides the performance horsepower to keep pace with Windows Server 2012 and multi-core processors. Additionally, 16GFC provides IT management the opportunity to reduce CAPEX and OPEX while seamless integrating it into existing Fibre Channel infrastructure. 6
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