8Gbps SAN delivers blazing speed

Posted on April 01, 2008

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By Jack Fegreus

Go from 0 to 8Gbps in 10 minutes with the HP StorageWorks 8Gb Simple SAN Connection Kit.

At most small to medium-sized business (SMB) sites, Fibre Channel-based SANs have long been viewed as complex and costly solutions that could be avoided by using direct-attached storage (DAS). That perspective has been reinforced by the ease-of-use of Microsoft Windows Server, which has left many SMB sites operating with a minimal IT staff. Worse yet, those same SMBs are highly risk averse when it comes to anything that appears to be a disruptive upgrade.

Nonetheless, the IT landscape at SMB sites is beginning to change dramatically. As CEOs focus on e-business for revenue growth and regulatory bodies expand the compliance burdens on records retention, mid-tier companies are no longer insulated from the explosive growth rate in storage. What’s more, IT decision-makers in mid-tier companies now find themselves no less under the gun to provide a demonstrably responsive IT infrastructure than their brethren at Fortune 100 enterprises.


Creating a logical disk using the wizard is a simple matter of choosing a data redundancy level—RAID 0, 1, or 5—a volume size, and name.
 

On top of that, the expansion of storage at SMB sites has made the volume of storage their biggest IT cost driver. It is not the acquisition of storage, however, that puts the greatest pressure on their budgets. The frequent tasking of IT staff to deploy new storage resources or repurpose existing ones validates an important rule of thumb for storage: Per-gigabyte management costs are three to ten times higher than capital acquisition costs.

Storage provisioning and management tasks are highly labor-intensive and impact minimally staffed mid-tier IT sites in a particularly burdensome way. What’s more, the old notion of holding down costs with DAS devices stands in stark contrast to the best practices of large data centers, where SAN technology is de rigueur for consolidating storage resources and streamlining management. As a result, the notion of networked storage has begun to make rapid inroads at SMB sites.

Nonetheless, SAN adoption at SMB sites is still constrained by a number of unique hurdles. First and foremost is the issue of disruptive upgrades. IT decision-makers at these sites are particularly concerned about the life span of any new technology acquisition. As a result, any new storage solution must meet all current and future performance requirements.

Also important is the issue of simplified end-to-end device management. For IT teams in small SMB shops, the power to configure and manage all devices using a single unified GUI cannot be over-estimated. For SMB sites, minimizing the number of administrators involved in a task takes precedence over minimizing the number of steps in that task.


Having created our first logical drive—a RAID-0 10GB volume—we ran oblLoad, a benchmark that generates transactions in a simulated database pattern. Using 8KB reads, we processed more than 60,000 I/O requests per second without having performed any custom tuning.

Along those lines, Hewlett-Packard has partnered with QLogic to simplify SAN management through a suite of wizard-based tools for the configuration and management of SAN host bus adapters (HBAs) and switches. HP has upped the ante for SAN adoption at SMB sites with the introduction of a future-proofed 8Gbps SAN infrastructure bundle that is priced at a level commensurate with 4Gbps SAN components. The HP StorageWorks 8Gb Simple SAN Connection Kit includes all of the components required to create up to a four-host SAN infrastructure with a connection to a single- or dual-controller storage target. More importantly, the CD that comes with the kit provides a one-step installation that discovers the underlying topology, installs all of the drivers and services needed to leverage that topology, and optimizes the SAN configuration.


During initial installation, the Simple SAN Connection Manager configured our host running Windows Server 2003 to distribute traffic optimally to each of the storage arrays over all available paths in our SAN.

Once installed on a management host, the Simple SAN Connection Manager software provides an easy-to-use wizard-based GUI to manage all SAN components. When combined with an HP EVA or MSA disk array, the SAN Connection Kit’s management GUI provides a single end-to-end management interface for all SAN switches, HBAs, and disk arrays. Whether provisioning RAID storage tiers or zoning a SAN at a switch, a single administrator can invoke a wizard to implement all of the steps needed to complete a task. What’s more, the wizards ensure all tasks are done correctly and optimally every time. As a result, the HP Simple SAN Connection Manager creates a highly automated, easy-to-manage SAN that imposes very little operational overhead on IT staff.

For risk-averse IT decision-makers at SMB sites, the new SAN components go beyond simply doubling the I/O throughput capabilities of 4Gbps SAN components. The HP StorageWorks 8Gb Simple SAN Connection portfolio provides significant new technology advantages to help ensure a long lifecycle free of disruptive upgrades.

Making SAN adoption all the more compelling for SMB sites is the announcement that VMware’s ultra-thin hypervisor software, VMware ESX 3i, will be integrated on 10 models of HP ProLiant servers and includes seamless, out-of-the box integration of VMware virtualization capabilities with HP System Insight Manager (SIM).

Virtual machine (VM) environments will further benefit from support for N_Port ID Virtualization (NPIV) within the HP StorageWorks 8Gb Simple SAN Connection Kit’s HBAs and switches. Via NPIV, administrators can create multiple virtual HBA ports for a physical HBA and monitor switch traffic for the virtual HBAs. In future releases of VMware, administrators will be able to zone a virtual HBA into a virtual SAN (VSAN) for a VM.

First step to SANity

For SMBs with small IT staff, the installation—let alone the optimization—of a first SAN can be a high hurdle. The trauma often starts at the first step of the SAN installation: the gathering of all of the equipment, software, and documentation that will be needed.

First, there are all of the arcane Fibre Channel hardware components and options needed for a SAN. There are questions of mode, diameter, and connectors for the cables. Once the cables are settled, the real fun begins as the newly appointed SAN administrator discovers that it is necessary to specify the proper transceivers to connect the FC cables to the FC switch.

Once all of the physical components are in place, there is the onslaught of configuration options for all of the various devices. Not knowing which options can be safely ignored, or how settings on an HBA might affect settings on a switch, can turn a routine event into an arduous task. With a myriad of unfamiliar options on topics from arbitrated loops to packet framing, the fear of possible errors can paralyze the most daunting administrator and halt any semblance of steady progress. Is it any wonder that the initial complexity associated with the configuration and maintenance of a SAN topology has led many SMB sites to prolong the use of DAS technology?

In stark contrast to the build-from-scratch approach, the HP StorageWorks 8Gb Simple SAN Connection Kit contains all of the necessary components for up to a four-host SAN:

  • 8/20q Fibre Channel switch (eight of 20 ports enabled) and Rack-Mount Kit;
  • Four single-port 81Q Fibre Channel PCI-e HBAs;
  • 10 8Gbps short wave SFP+ transceivers;
  • Six 5m multi-mode Fibre Channel cables;
  • Quick Start Guide and wiring poster; and
  • Simple SAN Connection Manager software CD.

The kit packaging makes physically connecting and preparing the SAN no more challenging than opening a box. The ability to offer a simple end-to-end boxed SAN solution rationalizes a SAN as a cost-effective SMB storage approach. Nonetheless, the real magic occurs when the Simple SAN Connection Manager software is launched on a host server.


Using 32 KB I/O operations with our oblLoad and oblDiskWrite benchmarks, we pushed full-duplex I/O to just over 1.6Gbps—about 840MBps for reads-and-writes simultaneously.
 

Once an administrator starts the HP StorageWorks Simple SAN Connection Manager application, the installation scripts literally discover and optimally configure everything necessary to start running a storage network. In our test scenario, we launched the program and waited about eight minutes before being presented with our first option by the Simple SAN Connection Manager.

In just eight minutes, all of the necessary drivers were installed, and the HBAs and switches were configured. Even our host operating system was optimized for the configuration at hand.

We were now ready to begin creating logical drives on our two HP StorageWorks 4100 Enterprise Virtual Arrays (EVA 4100s). At this point, a novice SAN administrator can invoke a simple wizard and begin creating logical volumes that have the redundancy characteristics of RAID level 0, 1, or 5 arrays. The wizard then steps the administrator through the process of virtualizing the volumes ownership by offering a choice of servers to which the logical disk can be “presented.” That’s all that’s necessary to bring a virtual volume online to be mounted and formatted on a host.

Taking that path, openBench Labs created a simple 10GB RAID-0 logical disk; mounted and formatted the new drive on a ProLiant DL360 server; and ran our transaction processing benchmark, oblLoad, on the new volume. Using standard 8KB I/O requests, we were able to process more than 60,000 I/O operations per second (IOPS) on the HP ProLiant DL360 server. Those results have profound implications for scaling up applications such as Oracle and Microsoft Exchange. Moreover, at that performance level, we were reading more than 500MB of data per second, which is greater than the throughput of one Fibre Channel port on the EVA 4100 array.


The Simple SAN Connection Manager wizards mask the underlying complexity of StorageWorks arrays when creating logical volumes. The details of the multiple disk “plexes” can be discovered by drilling down on the device.
 

With that one benchmark, we exposed the complexity of what had occurred behind the scenes during the initial eight minutes when running the HP StorageWorks Simple SAN Connection Manager. The wizard had discovered our topology: one server, one HBA port on the server, two storage arrays, two controllers on each array, and two Fibre Channel ports on each array. The wizard then configured the host operating system, Windows Server 2003, on our server with a Multipath I/O (MPIO) service that supported four possible data paths for each of our two storage arrays.

Thanks to that MPIO service, whenever we imported a logical drive from one of the EVA 4100 arrays, our OS would default to setting up I/O load balancing for that volume over all four possible paths based on shortest queue service time. We had done nothing to optimize our configuration, yet as our oblLoad benchmark demonstrated, SAN I/O was tuned like an F1 McLaren-Mercedes at the Grand Prix de Monaco.

As a result, we were easily able to reach full-duplex wire speed—8Gbps for both reads-and-writes simultaneously—by using our benchmarks to read-and-write data using several logical drives distributed over the two storage arrays. This validates the ability to use existing storage devices to scale I/O in a well-balanced fashion within our 8Gbps infrastructure.

While our performance benchmarks underscore the value of the HP StorageWorks 8Gb Simple SAN Connection Kit infrastructure as a platform for storage consolidation, the benefits derived from such a scalable SAN infrastructure border on the self-perpetuating. The data-intensive applications that drive the need for higher throughput are also the applications that benefit most from the introduction of the new SAN technology.

Services on our Windows server were not the only complexities that the HP StorageWorks Simple SAN Connection Manager optimally exploited and then masked. On both HP EVA 4100s the wizard presented a very simple dialog for the creation of RAID-1 disk arrays. This dialog entirely masked from the administrator a much more sophisticated process. The actual data redundancy structures that were under-pinning each of our logical volumes were mirrored multi-drive “plexes.” Hidden from view, the EVA had created striped multi-drive structures in a storage pool. As a result, our simple RAID- 1 volume was far more akin to RAID 10 than to RAID 1.

Even drilling down on the devices in a SAN is simplified by the Simple SAN Connection Manager GUI. From a clean and simple topological view, a SAN administrator can drill down and manage arrays, switches, and HBAs. More importantly for an SMB site, there is virtually no need to do that at any time. A novice administrator can—and perhaps should—work exclusively with the wizards and benefit from results that are characteristic of a perfectly optimized SAN.

Jack Fegreus is CTO of www.openbench.com. He can be reached at jack.fegreus@openbench.com.


OpenBench Labs scenario

UNDER EXAMINATION
8Gbps SAN infrastructure

WHAT WE TESTED

HP StorageWorks 8Gb Simple SAN Connection Kit

  • Complete hardware and software SAN infrastructure kit for up to four hosts and a storage array.
  • Wizard-driven GUI simplifies storage management tasks by masking optimization complexities.
  • Benchmarked full-duplex 8Gbps throughput: The HP StorageWorks 81Q HBA sustained simultaneous read throughput at 840MBps and write throughput at 825MBps.
  • Future-proofed for virtualization via HBA and switch support of NPIV, which will enable the assignment of virtual HBAs to VMs running on the host to create VSANs that can be zoned.

HOW WE TESTED

HP ProLiant DL360 G5 server
—Quad-core 2GHz Xeon CPU
—2GB RAM
—Windows Server 2003 SP2
—HP StorageWorks 8Gb Simple SAN Connection Manager
—QLogic Enterprise Fabric Suite 2007

Two HP StorageWorks EVA 4100 storage arrays
—Two 4Gbps controllers
—Two active-active ports per controller
—Eight 146GB 10,000rpm drives

BENCHMARK

oblLoad

KEY FINDINGS

  • Benchmarked full-duplex 8Gbps throughput: Sustained simultaneous read throughput at 825MBps and write throughput at 825MBps.
  • On installation, the Simple SAN Connection Manager discovered the entire SAN fabric topology and created an MPIO service on Windows Server 2003 for each EVA 4100 array.
  • Single wizard-based GUI simplifies optimal end-to-end SAN configuration and management of all arrays, HBAs, and switches.

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