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February 27, 2009
• Vol.31 Issue 9
Page(s) 30 in print issue
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Set Up A Basic SAN
These Experts Tips Can Make The Initial Process Less Confusing
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| Key Points
SAN setup is easier than ever. But that doesn’t mean network administrators with little or no background in the subject will be able to plug-and-play with ease. To get started, you’ll need to choose a protocol and either go through some training or enlist the help of a consultant. | | Thinking about setting up a basic SAN? You’re not alone.
Many IT managers still think SANs are too expensive for their small or midsized enterprises, but that’s not the case anymore, experts say.
Although the cost and complexity of SANs are dropping, they can still be uncommon outside larger enterprises, and that means on-staff storage experts may need to seek out a little help to walk them through the process of setting up a SAN.
That’s the message from Bill Smoldt, vice president of research and development at STORServer (www.storserver.com), which builds storage applications and helps small businesses back up virtualized servers in the SAN environment. Although setting up a SAN is easier than ever before—with vendors offering plug-and-play technology that really does perform as advertised—the SAN setup process can still be deceptively confusing for IT personnel who have never dealt with the technology and its terms, Smoldt explains.
“Running a SAN is different than managing storage in general, so it can be confusing for a novice,” Smoldt says. “There are some network administration concepts that are harder to grasp because [a SAN is] both a storage management tool and a network. Things like SAN zoning are foreign to the storage guys, because they’ve never had to zone before.”
Smaller sites often don’t have the means to employ a staffer dedicated to SAN administration, Smoldt explains.
“They have someone doing SAN two hours a week, and their manager isn’t going to send them to SAN training because it’s just a little SAN they’re working on.”
For these reasons, Smoldt recommends calling in a consultant to set up the initial SAN, especially if you will be using it to back up virtualized servers.
 Choose Your Protocol
Before calling in a consultant, ask yourself whether you’ll seek the iSCSI or the Fibre Channel SAN protocol for your connectivity layer, says Bob Woolery, senior vice president of marketing at Nexsan Technologies (www.nexsan.com). They both offer storage management features that include storage virtualization, automated tools, remote replication, snapshots, and storage pooling. These features allow for automation and for the SAN to scale, Woolery says.
iSCSI is more affordable than Fibre Channel (which is useful for powerhouse, high-performance applications) simply because iSCSI systems are sold at better price points, and you can connect them to an existing IP network, Woolery says.
Fibre Channel switches are more expensive than iSCSI switches, and acquiring the system and the infrastructure necessary to go around such a switch can also add cost, Woolery explains.
“Most people have a 1Gb network, which is OK for [an] iSCSI,” he says. “But if you need high performance, like you have big Unix servers and high-end application servers, you’re probably going to be looking at a Fibre Channel SAN.”
But experts differ about how things will shake out here. Low-cost Fibre Channel options are beginning to compete with iSCSI at the small to midsized enterprise levels, while iSCSI over 10 Gigabit Ethernet could pose a challenge in the future at the high end.
But Soon Pak, technical manager of enterprise storage at Antares Management Solutions (www.antaressolutions.com), says that although iSCSI is gaining momentum, Fibre Channel networks are still considered the premier solution.
Midsized enterprises need to focus on their own business requirements when making this connectivity choice, Pak explains. Depending on the server input/output requirements and trends, iSCSI can be a solid option.
Don MacVittie, strategic architect for F5 Networks’ DevCentral Core Team (www.f5.com), predicts the Fibre Channel protocol will eventually lose the race against iSCSI. MacVittie has long written about the storage solution industry.
“Not tomorrow, or even next year, but eventually data center managers are not going to want to maintain two separate networks,” he predicts. “Put in a Fibre Channel with a three- to five-year window in mind, and you’ll not suffer from this truth.”
MacVittie explains that the Fibre Channel protocol has its benefits, offering high-speed access to more disk space than the server could likely hold and centralized management of storage resources.
Fibre Channel Tips
Should you choose to implement the Fibre Channel protocol, MacVittie has a few tips.
One suggestion he has is to plan ahead. A SAN’s logical unit numbers are generally modifiable after creation, but it can be painful to grow them, he says.
“Make certain you have enough space on each LUN, not for today’s usage, but for two to three years from now,” he cautions.
Smoldt says that small-network administrators may not be familiar with terms such as “SAN” and may need to background themselves and seek training to get up to speed.
“SAN people talk in LUNs,” he says.
MacVittie explains that when implementing the Fibre Channel protocol, administrators must consider switch location, making certain they can easily run cable from the switch to every server that will be plugged into that switch. Install host bus adapters and drivers first. Take one machine down at a time and test that all work well with the HBA (host bus adapter) drivers installed. You can hook up the SAN at any time after this step, he says.
MacVittie also recommends asking your SAN vendor about management tools. All SANs are not created equal in the management space, so make sure you know what you’re getting. Although the SAN hardware is solid, software is the differentiator.
You’ll also want to avoid SAN virtualization. MacVittie explains that if the switch goes down, you may have more trouble than you can imagine getting your data back because the switch holds the list of where each bit of data is physically stored.
Regardless of the SAN protocol used, negotiate professional services as part of the technology purchase, Pak suggests. He counsels IT managers to approach vendors at the right time of the year. “Vendors are more willing to negotiate closer to the quarterly or fiscal year end,” he explains.
SANs can be helpful in a virtual server environment because they consolidate data and meet the required performance and capacity requirements, Woolery says.
Alas, setting up a SAN to back up a virtualized server means network administrators must carry out what Smoldt terms as “some very scary tasks for someone not versed in the SAN environment.”
In fact, MacVittie advocates training for any network administrator not versed in the ways of the SAN, as does Smoldt.
“There’s a threshold for getting over this learning curve,” Smoldt says. “In a virtual server situation, if you mess it up, you can wind up in a situation where your virtual server loses access to the storage. It’s a scary thing. I’ve had that happen.
“When we get into the zoning for backing up SANs, then we have to do some things that are totally counterintuitive to what a storage administrator would expect, like adding zones to allow the backup proxy server to see all the storage in the SAN and to access it directly. That’s a big, scary thing when you first go to do that,” he says.
“It’s so counterintuitive because you’re going to give another system direct access to your block-level storage and it feels like it could destroy all of your data,” Smoldt adds.
Pak leaves IT managers with this useful product tip: Some of the biggest impacts to a storage solution are often not even part of the storage area. A blade system with a virtual connection, for instance, can reduce storage and network connectivity costs by nearly 50% and can provide faster deployment and quicker system repairs, he says.  by Jean Thilmany
TOP TIPS
• If you’re attempting server virtualization, look at bringing in a consultant to help. • Network administrators not used to working with a SAN may need training before they set up an initial SAN on their own.
• Choose your connectivity protocol before you begin; expert opinions vary as to which work best with particular installations. • Become familiar with the terminology: SAN people talk in LUNs.
• Look at your overall storage solutions. Hardware choices can also impact network connectivity and reduce costs. |
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