RAM | Reseller Advocate Magazine: Issue 55

By Chris Angelini

A COUPLE OF MONTHS BACK, I SPENT some time exploring the wild world of storage, hashing out the differences between hardware and software RAID, integrated solutions touted as chipset value-adds, and discrete cards commonly costing more than a grand. I even uncovered a couple of products that have come in useful in my own consulting business—mainly Supermicro's Zero-Channel RAID card and Intel's ROMB hardware RAID upgrade.

But there's a big divide separating those who talk about something and those who actually get their hands dirty with it. That's the reason this column exists. Otherwise, it'd be like extolling the merits of cold fusion without showing that the technology is commercially viable. Your customers want results. When you demonstrate how a particular product might help save money or get a job done faster, you're already a step ahead of most other resellers.

We're revisiting storage controllers this month, bobbing and weaving past the explanations of why things are the way they are, when discrete cards are better than integrated solutions, and where to deploy hardware-based products instead of software. Instead, we want to tell the hands-on tale. How hard is it for resellers with little experience rolling out RAID to get the job done right? There's no room for error when it comes giving your customer a fail-proof infrastructure, making it imperative to be comfortable dealing with the latest technologies. From working with the hardware to configuring an array to administering in Windows, we'll get you up to speed.

The Hardware Hookup

In my experience working with SMBs and server hardware, the redundancy of data is either sadly underemphasized or an issue of hyper-sensitivity. In either case, it's usually up to the reseller to right-size storage depending on the application. If you're taking a customer online with a first server, the luxury of a blank slate lets you do things right the first time. Upgrade jobs can get a little trickier as you pick up where someone else left off.

Both situations require a detailed analysis of storage requirements, though, and an accounting of neighboring components. For example, does that two-year-old server you're upgrading accept PCI Express storage adapters? Probably not. You'd better make sure to procure a PCI or PCI-X RAID card. What about the disk interface? There's no point in pushing SAS aggressively on a project that only calls for a new pair of SCSI disk drives, right? Performing an audit before making any purchasing decisions helps prevent surprises as the hardware starts trickling in. And be thorough. We recently ran into a problem in our own office where a server chassis was so roomy that the cables bundled with our SAS RAID controller wouldn't reach the drives themselves, thus delaying the build by a whole week. That could have been an embarrassing field call.

Ain't Nothing Like the Real Thing, Baby

It's all well and good to talk about why this technology is great for SMBs and why that one might be a better enterprise play, but there's simply no substitute for getting the hardware and software running in a test environment to use as your customer might in the real world.

As a means to get you up to speed on the ins and outs of RAID from the three top vendors, I set up a true SMB server—one configured to run in a production environment. The server centers on Supermicro's SuperServer 6014H-32 chassis, a relatively simple 1U barebones box with enough room for two PCI-X or PCI Express add-in cards. I added two 2.8 GHz Intel Xeon DP chips based on the Paxville core along with a gigabyte of Corsair's DDR memory. The system's backplane is already set up to accommodate SAS or SATA drives, so testing those technologies is a piece of cake. SCSI requires that the drives be stacked externally with a separate power supply driving the whole machine, as Supermicro's PSU is optimized for the 6014H-32 chassis and doesn't have enough four-pin connectors. Seagate was kind enough to send a trio of 500GB SATA, 146GB SAS, and 146GB SCSI drives so that I could test each configuration using RAID 5.

SATA 3 Gbps and AMCC's
3ware 9550SX

I love high-end disk technology. From the cutting edge interfaces architected to enable optimal bandwidth to the super-fast spindle speeds, it's always fun to push a PC's most bottlenecked subsystem a little bit faster. But not every one of your customers wants to pay the premiums associated with the best storage hardware. Instead of 15,000 RPM SAS drives, you might suggest a well-protected SATA array. Though inherently less enterprise-oriented, running a RAID 5 setup affords enough redundancy to keep most small businesses protected, while still enabling solid performance.

Eager to prove that mainstream SATA technology is perfect for uncompromising SMB customers, AMCC sent its 3ware 9550SX controller card, a PCI-X board decked out with eight ports. It's architected using the company's 7th-generation switch fabric technology and is claimed to be 200% faster than its predecessor.

What we're looking at, however, is the 9550SX's behavior in a production environment. What makes the card a reseller-friendly solution? To which of its features are customers most likely to respond? Is there a reason to spend upwards of $500 on a SATA card when most server boards give you SATA RAID as a built-in chipset feature?

I'll answer that last question first—absolutely. To be honest, I had my doubts initially, too. But after running Iometer on the AMCC card and Intel's integrated ICH7-R south bridge, I wouldn't hesitate to recommend hardware RAID in an SMB environment. Most telling is the CPU utilization scores. AMCC's 3ware 9550SX used just .06% of our server's processor time while the software-based RAID solution, also run on a dual-core platform, consumed 16.13%. The 9550SX yielded 136.37 I/Os per second whereas integrated RAID enabled 89.84. The hardware add-in card boasts lower response times to boot. If you look only at raw benchmark data, a solid disk controller is worth every penny.

But the story gets even better as you start working with management. I've had customers lose data on more than one occasion at the hands of specialized software vendors. Without fail, they'll almost always point a finger at the consultant, claiming a bad disk controller or hard drive was to blame. Immediately after, configuration report in hand gleaned from my disk controller's management console, I'm able to confirm the hardware is functioning as it should. The vendor almost always “finds” a bug in their code a couple of days later.

That's the sort of power you get from a business-class card, such as AMCC's 9550SX. Installation is a breeze, especially on a 1U box already configured with a backplane. Simply unplug the built-in controller and re-connect each of the ports to your add-in solution. Be aware that the software setup is a little more complicated—even under the latest build of Windows Server 2003 R2, drivers for the 9550SX aren't automatically installed. VARs need to download the latest driver from AMCC's Web site (www.amcc.com), copy it to a floppy (use an external USB floppy if your servers don't include one), and actuate Windows' F6 setup prompt to add the requisite software. Of course, AMCC also acknowledges several Linux builds, FreeBSD, and 64-bit versions of Windows with official driver support.

With an operating system installed and running, deploying the 3DM 2 management utility is a piece of cake. A Web-based interface is simple, intuitive, and yet powerful enough to let you schedule rebuilds, delegate controller resources, and monitor the error log. Because of its universality, you can use 3DM 2 from anywhere. There's no client software to install. If the server is accessible from the Internet, the AMCC card is, too.

SAS and Adaptec's 4800SAS

You'd think that SAS, having been dubbed the successor to SCSI, would find itself pigeonholed into high-end servers and workstations. But one of the reasons vendors and resellers alike expect it to make such a huge impact on storage in the months to come is that it extends compatibility down to SATA hardware. In turn, we're seeing an almost universal message from the big names in SAS: Sell your customers SAS cards today, even if they're only using SATA drives. The controllers aren't much more expensive and support for mixed SAS/SATA environments protects future expansion. SAS basically lets you build value into your beefier systems.

Better still, the subtle difference between SAS and SATA connection equipment makes the reseller's job much easier. In a SCSI world, you had to get cozy with unwieldy cables, IDs, and terminators, shifting over to 80-pin cables and short runs on a separate controller to add IDE. SAS is serial, so whether you're attaching SAS or SATA drives, the connections are all point-to-point across similarly thin cables that might stretch a meter in length.

Adaptec shipped its 4800SAS card as an example of SAS' utility in the SMB space. Selling at prices under $1,000, customers will pay a premium over SATA-only RAID controllers. However, hardware results versus software-based core logic amplify when you adopt an even more intensive storage infrastructure. And because there aren't any chipsets with built-in SAS, an add-in card becomes necessary, anyway.

So does the 4800SAS really deliver on its promise of setup simplicity, interoperability, and high-performance? On all three accounts, yes. You'll once again need to supplement Windows' dated driver package with the latest from Adaptec using a floppy disk. But the physical installation and subsequent BIOS configuration routine are both intuitive enough even for a storage greenhorn. Some of the BIOS setup options may look foreign to VARs who've typically focused on desktop hardware, but I found the default settings to work well enough for testing.

The bundled accessories are suitable for connecting up to eight hard drives—SAS or SATA, it doesn't matter since the cables accept both. Of course, the Adaptec Storage Manager suite is also included, giving you an ultra-clean interface from which you're able to manage attached drives either locally or remotely. I even added a second Adaptec card to the management window, just to test the app's handling of a higher-end configuration consisting of multiple controllers. The Storage Manager recognized each board's unique features, along with the connected drives and arrays. Note that many barebones chassis feature onboard Adaptec storage logic. Adding an Adaptec card upgrade down the road is a good way to consolidate management, add hardware acceleration, and still make use of the two controllers.

As expected, the 4800SAS performs like a champion. Hardware utilization in Iometer stayed well below 1% and response times hovered just above 4 ms. The I/Os per second jumped to a phenomenal 249—a massive leap compared to SATA technology. So while there's plenty of reason to guide more budget-sensitive customers toward SATA, you clearly have data available to show how a SAS subsystem can help improve performance.

SCSI and LSI Logic's MegaRAID
SCSI 320-2X

For all of the fanfare behind SAS and SATA, you'll still find that SCSI is the most prolific disk interface amongst customers with established servers and workstations. When they aren't looking to replace those boxes, an upgrade is often in order. And seeing that the drive vendors haven't written SCSI off yet, you may very well want to stay involved with the technology until it no longer makes sense to your customers. After all, you can continue to offer many of the same features. Take LSI Logic's MegaRAID SCSI 320-2X, for instance. The dual-channel PCI-X board is as laden with advanced functionality as any other card I've tested. In addition to supporting the standard arrangement of RAID modes (RAID 0, 1, 5, 10, and 50), LSI Logic also claims IA-64 readiness and compatibility with Microsoft's Cluster Server software. You can assign up to 40 logical drives per controller and assign a maximum of 30 disk drives to each array.

Of course, it'd be silly to pretend that SCSI is as user-friendly as either SAS or SATA. But customers interested in a SCSI solution are likely looking to save some money by repurposing an existing infrastructure, so even when you factor in the cost of SCSI cabling, you're still adding value overall. The MegaRAID SCSI 320-2X at least comes with a quick setup guide to walk you through jumper configuration, setting SCSI IDs, and terminating the bus. For all of the technology's little intricacies, getting LSI Logic's board up and running is really quite easy.

Moving forward, representatives at LSI Logic are dedicating increasing attention toward SAS. The company sent its newer MegaRAID SAS 8308ELP card as an example. Most striking is the board's super-low profile, which is perfect for 1U boxes like the one I use. It offers massive power—RAID 0, 1, 5, 10, and 50 support, accommodations for arrays larger than 2TB, 128MB of buffer memory onboard, and a x4 PCI Express interface. (PCI Express works great on servers that support it; remember that older boxes might only work with PCI-X.) More practically, the card comes with unique connectors that compact the usual quartet of SAS/SATA ports into a much smaller bundle. Snaking around the space constraints of a 1U box is no problem at all. Additionally, the bundled cables are easily long enough to span a standard chassis.

Looking Back

Performance is rarely discussed when it comes to storage. There are so many different possible drive configurations, and, of course, the workload you apply to a platform massively impacts results. At the same time, it's important to show customers that their choice in disk technology will play into a server's speed. You'll also want to talk about the pluses and minuses of hardware acceleration versus software. Once again, the differences are clear, and for businesses with a lot going on, saving CPU cycles means more horsepower for other tasks.

I was particularly surprised at the ease of use improvements that AMCC, Adaptec, and LSI Logic have all made to their respective products since I first started dabbling in storage. Resellers should have very little trouble configuring any of the SATA, SAS, or SCSI boards I tested. The near universality of RAID 0, 1, 5, 10, and 50 support gives you plenty of room to pick and choose the right mode for your customer's environment, too.