2 Nov, 2011
Storage networking is facing a looming transition to converged architectures that bring together storage and data traffic. Convergence offers management and cabling simplification, but introduces performance risks for storage traffic that has typically run on segregated networks. Performance requirements for high-capacity data and storage networking equipment are much more closely aligned with the advent of 10-Gigabit Ethernet and 16Gbps fiber channel (FC). With the release of the 16Gbps FC standard, FC vendors have the ability to update chipsets and products and include support for 10GigE on the same hardware – common silicon with support for both standards can be built, with software providing configuration control. QLogic has introduced a new Converged Network Adapter (CNA), a new stackable switch and an updated router with cross-storage-technology functionality, all poised to address the transition to a converged network.
The FC market continues to generate solid sales volume, with the transition to the previous-generation 8Gbps equipment in full swing. Preliminary results from the currently active storage study (Wave 16) by TheInfoPro (a division of The 451 Group) indicate that more than half of the respondents have implemented 8Gbps FC somewhere in their environment. The next buying decision for storage networks is whether to continue on the FC path or to step toward the promise of a converged storage and data network. The study is indicating that 10GigE and fiber channel over Ethernet (FCoE), a transitional technology that carries FC traffic over an Ethernet network, appear equally in storage plans, with one in five respondents reporting they plan deployment within the next two years; 8Gbps FC sees a similar number of plans for deployment. Spending for 16Gbps FC is much further out, with over 30% reporting beyond 2013 and over 40% indicating that they have no current plans to make the move.
The 451 Take
With 16Gpbs FC gear just becoming available, migration beyond 8Gbps storage networks is nascent, at best. The new products introduced by QLogic should be attractive to those who want to buy equipment that will support their FC infrastructures today and hedge their bets with an upgrade path for both converged and 16Gbps FC networks. Converged network adapters are a choice for those users who expect to eventually transition high-value servers to converged storage. Converged switches are a tougher sell. Concerns about management and integration capabilities will limit the impact of any advantages over core networking vendors. Where storage teams win those buying decisions, QLogic could play well. If network teams win, traditional data networking vendors may take the day.
QLogic's new FlexSuite family of CNAs supports a range of interface types. The optical version of the card uses small-form pluggable (SFP+) connectors. These pluggable interfaces allow either FC or Ethernet optic modules to be used in the same card. The cards have two ports that can be configured independently. A single card can have a 16Gbps FC and a 10GigE port running simultaneously. A copper interconnect version of the card is available with either Direct Attach ports or 10GBASE-T ports. The adapters all support PCIe Gen3 host bus capabilities, and can support processor offload for network protocol and encryption, including IPSEC offload. There is limited support for interface virtualization using NPAR (NIC Partitioning) and VEPA (Virtual Ethernet Port adapter) functionality, and up to 16 virtual segments can be created. NPAR allows each physical interface to be configured to appear as multiple, separate interfaces to the OS or hypervisor. This configuration is performed within the adapter. VEPA takes a further step to network virtualization and allows capable hypervisors to signal virtual interface configurations through the adapter to a physical switch that must also support VEPA signaling. While it adds some flexibility in having the underlying physical network infrastructure make switching decisions, it has the drawback of requiring inter-VLAN traffic to exit the virtual server to be switched by the physical switch.
The next step in interface virtualization, SR-IOV (single root I/O virtualization), is not available, but is promised in a future update. This lack will be important to users in high-performance virtualization environments using Microsoft's Hyper-V 3.0, Citrix's Xen or Red Hat KVM hypervisors. On these platforms, much higher network throughput can be achieved with SR-IOV's ability to provide more efficient access to virtualized network interfaces when compared with NPAR. VMware has yet to offer full support for SR-IOV in vSphere 5.
FlexSuite adapters have substantial power and flexibility, and will undoubtedly find homes in many higher-capacity servers. They will be a natural upgrade path for current QLogic users. The independent port configuration would allow a virtualized server to have a single adapter that could connect to SAN-based storage over FC, as well as a data connection over 10GigE. For the SFP+ cards, that same adapter could have one or both ports converted to a converged FCoE interface by switching the optics, which are currently priced in the $200-500 range.
Switch and router
The UA5900 switch is a flexible, high-density, stackable device. It offers 52 SFP ports that can be configured for either 16Gbps FC or 10GigE, and has four QSFP ports that can be used as inter-switch links for stacking or be broken out for an additional 16 standard ports. These ports can also be used as 40Gbps Ethernet uplinks when used as a top-of-rack Ethernet switch. Up to six units can be stacked together and managed as a single unit.
In its basic configuration, the switch treats FC and Ethernet ports as independent switches. The addition of a converged networking license enables FCoE capability within the switch. This allows FC traffic from an FC port to be carried across the Ethernet network to an FCoE-enabled host. The switch supports datacenter bridging standards for queuing and prioritization to deliver more reliable transport for FCoE traffic.
The Intelligent Storage Router (iSR) 6200 is a platform update to the QLogic iSR line that adds increased port speeds and FCoE capability. The iSR has been used as a bridge between iSCSI and FC storage realms, and as a WAN link between datacenters. The update increases performance and adds interconnection to converged storage networks with FCoE. The WAN link capabilities have found use in replication and disaster-recovery applications, while the storage bridging seems to be a more specialized function for customers who are transitioning between storage technologies.
Competition
The storage networking market is in considerable turmoil. Traditional FC purchasing is going strong, particularly in the enterprise market. Storage and data networking convergence is creating uncertainty for future buying trends. Buying decisions in converged environments have the potential to shift from storage teams to networking teams. This means that equipment cost advantages may help capex decisions, but established networking vendor relationships and management infrastructures can trump all but the most glaring motivations.
In the CNA market, Broadcom, Brocade, Emulex and Intel have offerings that can compete with QLogic. There is a pitched battle taking place to secure both the host (servers) and target (storage systems) business with OEMs such as Dell, Hewlett-Packard, EMC and IBM for 16Gbps FC. This is occurring around both adapter cards and chipsets that will be integrated into systems in LAN on Motherboard (LoM) configurations. OEM business is a large portion of the revenue for each of the CNA vendors. All have now announced new products to compete for this business because, while end-user buying is some ways off, OEM design decisions are being made now.
Emulex is QLogic's main competitor for FC and converged products. It emphasizes performance and takes a simpler view of product mix – not offering a single adapter with combined FC and Ethernet support, and skipping any switch product in its offerings. Its recently announced 16Gbps FC dual-port adapter focuses on performance, advertizing over one million I/O operations per second, but supports only FC today. It has a growing 10GigE business, hitting 16% of total sales in the most recent quarter, but it keeps Ethernet and FC product lines distinct. Its strategy has been that customers will buy products to meet current needs, rather than spending on equipment with an option to transition to new technologies in the future.
The broader question is whether CNAs are also competing with single-function 10GigE adapters. In current implementations, the optics cost of the adapter is a large portion of the total price for both FC and Ethernet. As implementations of copper-based 10GigE (10G BASE-T) mature, there will be a significant cost advantage to single-function copper adapters. Today's copper adapters come with a large penalty in power consumption, as much as double in some implementations, and this makes them unattractive in high-density use, such as datacenters. Advances in silicon geometries continue to shrink this gap, but it will persist well in to 2012. Intel's acquisition of Fulcrum Microsystems is a quiet bet that the cost advantages of copper will eventually win out.
The 10GigE adapter market is expanding considerably, with a growing set of vendors. Some have already established OEM footholds, such as Solarflare Communications' mezzanine modules for both HP and IBM blade servers. This is a much more competitive market, as QLogic tests the waters outside of the traditional storage space. It has a reasonable claim to the lead in market share in FC adapters, which make up more than 85% of its business today, but they're not as well known in data networking. Some vendors, including Intel, Emulex and Solarflare, already offer higher performance capabilities, like SR-IOV, that will create challenges.
QLogic faces a similar situation selling switches. Cisco and Brocade are its main competition in FC SAN switches, and the UA5900 offers advantages over both in flexibility and density. Competing products have limited numbers of ports that can be changed from FC to Ethernet, giving QLogic an advantage. They face challenges in integrating multiple switches for Ethernet environments. Both Cisco and Brocade can extend their interconnections across multiple systems with 'fabric' architectures, FabricPath and VCS, respectively. QLogic correctly identifies both of these as proprietary functionality, but with HP's recent announcement of support for Cisco's fabric connections in its BladeSystem products, this is no longer a single-vendor offering.
Connections to upstream switches are an area of larger concern. QLogic can use link aggregation protocols to form higher capacity links to a network core switch, but this will perform less efficiently than either of the competing solutions from established vendors. QLogic also has no announced plans for support of the recent IETF Transparent Interconnect of Lots of Links (TRILL) protocol. This provides multipath traffic utilization that any larger network installation will require, and is an alternative to proprietary fabric capabilities. This puts the UA5900 in the position of not being able to offer the performance of the proprietary features, as well as operational integration.
Virtualization will continue to impact networking decisions for both data and storage, and will drive the move to convergence over time. Hosting and cloud providers are leading a move away from the traditional large FC SAN storage toward iSCSI and, in some cases, direct-attached storage. This shift will likely limit long-term growth in FC, and may prompt a jump that skips transitional plays and goes straight to a converged storage environment.