iscsi Top Ten Top Ten reasons to use Emulex OneConnect iscsi adapters

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1 W h i t e p a p e r Top Ten reasons to use Emulex OneConnect iscsi adapters

2 Internet Small Computer System Interface (iscsi) storage has typically been viewed as a good option for small and medium sized businesses or branch-office deployments. However, as shown below, advances in the iscsi infrastructure have accelerated growth of the iscsi market and led to wider adoption of iscsi storage for larger data centers. $6 iscsi Worldwide Revenue ($B) Source: IDC (2010) $5 $4 $3 $2 $1 $ This white paper presents a Top Ten list of key trends that are driving iscsi as a strategic technology for networked storage and highlights important benefits that are provided with Emulex OneConnect 10 Gigabit Ethernet (10GbE) iscsi adapters. 1. Cost Savings iscsi has earned a reputation as the low-cost SAN. Specifically, iscsi combines lower upfront capital expense with ongoing operational savings when compared to Fibre Channel. iscsi is based on standard Ethernet technology and can be used with existing switches and cables that support an IP based network. IT staff can also leverage their IP networking expertise to support an iscsi SAN, reducing training and personnel costs and simplifying management Gigabit Ethernet iscsi was introduced for 1GbE networks with multipathing and link aggregation enabling support for up to 4Gbps with multiple adapters. At the same time, Fibre Channel storage transitioned from 2Gbps to 4Gbps, followed by 4Gbps to 8Gbps. Not surprisingly, iscsi was typically used for less demanding applications that did not require the bandwidth that Fibre Channel provided. 2

3 The bandwidth comparison between iscsi and storage has changed with the introduction of new 10GbE iscsi adapters and storage arrays. For the first time, iscsi can run with higher bandwidth than Fibre Channel, and iscsi bandwidth leadership should continue with future transitions to 40Gbps Ethernet and 16Gbps Fibre Channel. 3. Server Virtualization Server virtualization has become a mainstream technology for optimizing resources and reducing costs in the data center. A recent survey 1 of 1,602 data centers for midmarket (500 to 999 employees) and enterprise-class ( 1,000 employees or more) organizations showed nearly three-quarters (74%) use server virtualization. An additional 19% of organizations are in the evaluation or planning phase. Is your organization currently using x86 server virtualization technology? 7% 7% 12% 13% 61% With production servers With test/dev servers Evaluating or piloting Planning No plans The full benefits of server virtualization are only realized with networked storage. This includes key features such as virtual machine (VM) migration to optimize server resources and support for disaster recovery. iscsi can be used with all of the major server virtualization platforms and is fully supported with all storage-related features. When combined with 10GbE networks and new multi-core servers, data centers have the network and storage bandwidth, and the CPU resources, to reach much higher virtualization ratios. 4. Hardware iscsi A dedicated iscsi adapter provides significant performance improvements relative to a network interface card (NIC) and an iscsi software initiator. This includes reduced CPU usage with full offload and hardware acceleration for iscsi, TCP Offload Engine (TOE) and TCP/IP processing. iscsi adapters also use a separate software stack that optimizes performance for operating systems and hypervisors. In contrast, software initiators work with the same TCP software stack that s used for all network traffic, creating the potential for bottlenecks and contention for server resources. The performance benefits of a hardware iscsi adapter are particularly critical to optimize virtual servers deployments. To help quantify this benefit, Emulex Labs conducted a series of benchmark tests evaluating the maximum number of VMs that could run concurrently with a constant I/O rate using the Emulex OCe11102-I iscsi hardware adapter and a software initiator using a standard NIC. The maximum number of VMs was reached when the I/O throughput dropped below the constant rate of 10,000 I/Os per second (IOPS) for 4Kb block sizes and 5000 IOPS for 8Kb block sizes. Emulex OCe11102-I iscsi adapter ran 58% more VMs using a 4Kb block size and 10,000 IOPS per VM. With an 8Kb block size and 5,000 IOPS per VM, the OCe11102-I ran 53% more VMs. 1 Enterprise Storage Group, The Evolution of Server Virtualization, November

4 VMs Emulex OCe11102-I 10GbE NIC 5 0 4Kb block 10,000 IOPs 8Kb block 5,000 IOPs 5. Boot from SAN Boot-from-SAN (BFS) is a key iscsi feature that allows servers to boot off a remote disk. Although iscsi BFS is supported with iscsi initiators and NICs, it s much easier to deploy and manage with an iscsi hardware adapter. With an iscsi initiator, the NIC, passes parameters during the boot process that the host uses to establish a connection with the iscsi target. The process is somewhat different for each operating system on hypervisor With an iscsi adapter, BFS configuration is done in a pre-boot environment using the same technologies that have been perfected over many years with Fibre Channel SANs. Reliability is enhanced when the same connection and settings for the iscsi target are used before booting, during the boot process and when the operating system or hypervisor is running. Because BFS is managed pre-boot, it works the same way for any operating system or hypervisor. 6. iscsi over DCB As a best-efforts networking technology, Ethernet occasionally drops packets that require retransmission. Although not a concern for most Ethernet traffic, this can be a significant problem with applications that require consistently high performance. When iscsi traffic contends with other I/O on the network, there can be packet losses that lead to retransmissions and higher latency. The solution can be found with Data Center Bridging (DCB) standards that enable lossless Ethernet and virtually eliminate retransmission of dropped packets. DCB standards were developed by the Institute of Electrical and Electronics Engineers (IEEE) and were originally used to support Fibre Channel over Ethernet (FCoE). iscsi solutions are now available based on DCB standards that include the following: Feature Benefit IEEE Standard Data Center Bridging Capability Exchange capabilities and configuration of DCB features 802.1ab Exchange (DCBX) between devices Priority-Based Flow Control (PFC) Manage I/O between initiator and target on a multi-protocol 802.1Qbb Ethernet link (enables lossless Ethernet) Enhanced Transmission Selection (ETS) Allocate bandwidth based on priority groups 802.1Qaz iscsi TLV Separate iscsi traffic from LAN traffic in an Ethernet flow 802.1ab In addition to consistent low-latency performance, DCBX supports priority groups and bandwidth allocations that can be assigned in DCB-compliant switches. The switch communicates these settings to server adapters and storage arrays for automatic configuration, reducing the cost and complexity to maintain large-scale deployments. 4

5 7. Universal Multi-Channel NIC Partitioning Emulex OneConnect OCe11102 adapters support NIC partitioning with the switch-agnostic Universal Multi-Channel (UMC) capability that is based on the IEEE 802.1Qbg standard and allows multiple PCI functions to be created on each adapter port. With the OCe11102-I adapter, each port presents one iscsi function and three NIC functions to the operating system or hypervisor. UMC provides added granularity to bandwidth allocation provided by the ETS capability of DCB. With ETS, all of the iscsi traffic is included in the same priority group. With UMC, bandwidth can be allocated to specific network functions within the group. A typical use case would be VMware vsphere deployments with NIC and iscsi functions dedicated to high-demand VMs, cluster support, VM migration and system management. NIC, iscsi or FCoE NIC NIC NIC 8. Wide Area Networks Because it s based on Ethernet, iscsi is particularly well suited for several key deployment scenarios that require data to be transmitted over longer distances. These include: n Remote offices Allows storage resources to be managed at a central location with a full complement of IT staff. Remote servers or desktops can access data using high-speed WAN links. n Remote backup In some cases, remote offices may choose to use local, direct-attached storage but will rely on backups done by the data center. iscsi enables remote backup with TCP/IP networks that are easy to deploy and manage. n Disaster recovery Every organization should have a plan for disaster recovery. To support best practices, secondary sites should be located a safe distance away from the primary data center to ensure isolation and protection from natural and man-made disasters. 5

6 9. Unified Management The success of iscsi is grounded on the ubiquitous Ethernet infrastructure whose management and processes are well understood by IT professionals. As part of the OneConnect iscsi solution, Emulex is leveraging its expertise in scalable enterprise management and enabling it for iscsi deployments. Emulex OneCommand Manager provides a scalable centralized management platform for administration of Emulex OneConnect iscsi adapters across all major operating system and virtual server platforms. OneCommand Manager can also be used to manage Emulex Fibre Channel HBAs, FCoE CNAs and 10GbE network adapters from the same management console. Traditional iscsi management tools are native to the OS platform and provide local host management only. This means that the IT administrator must login to each and every server in order to perform any configuration of the iscsi adapter. With OneCommand Manager, IT operations can: n Manage all adapters throughout the data center from a single console regardless of OS. n Easily view iscsi ports using the OneCommand Manager Graphical User Interface (GUI), enabling storage data paths to be viewed from a server perspective. n Streamline management by scripting standard management activities using the OneCommand Manager Command Line Interface (CLI). 10. Growing Ecosystem With iscsi storage shipments forecast to approach $4B in 2012, the iscsi ecosystem continues to grow. Nearly every major storage vendor is shipping iscsi storage solutions including Dell, EMC, Fujitsu, Hitachi/HDS, HP, IBM, NetApp and Oracle. Another major sector in this growing ecosystem is the Ethernet switch, where a managed Layer 3 Ethernet switch is sufficient for most iscsi implementations. Ethernet switch products supporting iscsi are available from Arista, Cisco, Brocade, Extreme Networks, Force10 Networks, Fulcrum Microsystems, Juniper, Nortel and Voltaire. Emulex iscsi adapters are designed to be fully compatible with all of these products. 6

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