NAS devices offer big storage on small networks

We are collecting and keeping more information today than ever before. Whether it's video, pictures, music, or just plain old gobs of e-mail and text messages, all that information has to be stored and backed up.

Even in a down economy, the obvious temptation is to rush out, grab a handful of hard drives (no matter what the sizes) and hook one up to each of your computers -- especially since storage is now really cheap. If you look around for a deal on a hard disk you can sometimes find an external 1TB unit for only a little over US$100. But while that may sound like a plan, if you take that approach you're effectively fragmenting your life. (As the owner of 11 computers, I can pretty much vouch for that being the case.)

The better idea, assuming you are networked, is to take a tip from enterprise-level IT and latch on to some network-attached storage (NAS). In fact, a number of NAS units suitable for households and small businesses have recently hit the market. These devices don't have the capabilities or the features of the enterprise-level NAS units, but they offer higher performance and a lot more storage than your typical external USB backup drive at reasonable prices.

A NAS storage device typically holds more than one drive; some come already equipped with hard drives, while others are simply empty boxes waiting for you to choose the drives that go inside. The number of drives can vary -- some units max out at two drives while some stretch to five.

RAIDing your drives

These multiple-drive devices store your data in different ways, depending on the RAID technology schemes they use.

The two-drive units typically support only RAID 0 , which "stripes" the data across both drives and utilizes about 93% of the space available, and RAID 1 , which mirrors the contents of one drive onto the other so you can quickly recover from a crash and thus uses about 47% of the drives' capacity.

NAS boxes that can handle three or more drives can typically step up to RAID 5. As with RAID 0, RAID 5 offers striping, which improved capacity and performance, but it also reserves some disk space for parity bits. If one drive fails, you can recover all of your data from the remaining information from the surviving disks plus the data supplied by those parity bits. In other words, with RAID 5 you get the best of both worlds -- you get the chance to restore your data as in a RAID 1 setup and the increased space of a RAID 0 setup.

NAS units tend to have other technologies in common. Most feature Gigabit Ethernet , making a 1Gbit/sec. transfer speed available. And most come with their own backup applications.

While I'd encourage you to try the software that comes with a NAS unit, you're not married to any proprietary or pre-supplied backup software. You can choose among anything that's available that recognizes network drives and find something you like from that superset rather than settle for what you're handed.

For this roundup, I looked at three recent NAS units: Promise Technology's SmartStor NS2300N, Iomega 's StorCenter ix2 and MicroNet Technology's MaxNAS. Somewhere among these three could be the NAS unit you've been desperately seeking -- even if you haven't realized it yet.

How we tested

All of the PCs and the NAS devices used in these tests were connected via a hardwired Ethernet network using a Linksys EG800W switch. I decided against a Wi-Fi connection because, in the past, I've suffered through a number of anomalies only to find out at the end that it was the wireless connection at the bottom of them all. While Wi-Fi is more than suitable for typical file storage needs, it's difficult to recommend Wi-Fi for multiple streaming events, especially in the already crowded 2.5-GHz band.

To test performance, I timed how long it took to copy a 934MB file from the PC to each NAS unit and to copy the file back to the PC. Then I repeated the procedure while streaming a video from the NAS box to a different PC.

Since each of these NAS units also had media and/or iTunes "server" capabilities, I streamed multiple songs or videos from the devices to several PCs on the network. At one point, I had four different videos streaming off a unit into four different PCs. In no case was there any evidence of lagging or hiccupping or anything else that might be impeding the media experience.

Iomega StorCenter ix2 Network Storage

Iomega was once known for its Bernoulli Box and Zip drive -- two devices that offered higher-storage capacities to those unwilling or unable to use tape drives. Today, the company offers the StorCenter ix2, an NAS box available in 1TB ($299) and 2TB ($479) versions.

Iomega's pricing is very competitive with Promise's. The difference is that while Promise offers a hollow NAS box with a "Bring Your Own Disk" feature to keep pricing low, Iomega's StorCenter is populated and ready to run when you unbox it. However, while this makes the StorCenter very simple for the technological newbie, it's a feature that may not appeal to everyone.

To begin with, the box is closed -- it doesn't have a pop-open faceplate as do Promise's SmartStor NS2300N and MicroNet's MaxNAS . It's not completely sealed -- there are four Phillips screws on the back panel -- but you'll have to do real work to get in there if you need to replace one of the disks.

Then there's the upgrade issue. The ix2 supports RAID 1 mirroring (one drive is used for your data, the other "mirrors" its contents) or JBOD ("just a bunch of disks," formally known as spanning -- where the two disks are treated like one large one). In other words, if you're looking for data redundancy, a 1TB ix2 will leave you with 500GB available and a 2TB device with 1TB of free space. If you buy the 1TB unit and then later decide that you need more storage space, you'll have to either stop mirroring the drive or replace one of the disks.

Finally, Iomega's warranty only covers one year -- less than most hard drive warranties. For example, the two 1TB Seagate drives inside the StorCenter ix2 each carried a five-year warranty.

Iomega's software offers the easiest installation routine I've seen. The press release claims there are only four steps to getting the ix2 recognized by your computer -- and, by golly, this is one of the few times I've ever encountered software that lives up to the PR claims.

If you need to access the ix2's information or to change settings in the future, you just click on the "Iomega StorCenter Manager" icon in the Task Bar. Iomega has created an extremely user-friendly environment within the management software: all icon-based with rollover descriptions of what each function can accomplish. Even setting up a printer or a hard disk on the ix2's USB ports is relatively brainless.

As far as performance is concerned, the ix2 was the Momma Bear of the three NAS units tested. It was considerably slower than MicroNet's MaxNAS during writes but faster during reads. It was faster than Promise's SmartStor in both reads and writes, whether it was streaming video in the background or not.

I don't like Iomega's warranty, considering it's selling a basically sealed unit. However, considering the price and performance points of the ix2, it gets a recommendation for mainstream SOHO or bottom-tier SMB applications.

MicroNet MaxNAS RAID with iSCSI

MicroNet has been around for about 20 years; you might know the company better for its line of Fantom external drives than its hardcore disk array and networking products. If I had to categorize the MaxNAS, I would probably label it "some assembly required."

The unit arrived in a tall brown box with the actual NAS enclosure at the bottom and an upper-foam compartment that housed and protected the five Western Digital WD5000AVS drives waiting to be installed. These are 500GB hard drives with an 8MB buffer -- one of Western Digital's "Green Drives" -- and with five you have a total of 2.5TB possible. It's priced a bit on the upscale side at $1,349, but the available options are somewhat more upscale as well.

Along with the more common RAID 0 and 1, the MaxNAS also supports RAID 5 (single-drive failure tolerance), RAID 6 (allows for two drives to fail), RAID 1+0 (a combination of 1 and 0), JBOD and Span drive assignments.

Beyond that, the unit ships with three USB ports -- two at the rear, one upfront -- for attaching additional drives or a printer. You can copy the data from any storage device connected to the single front-mounted USB port by pressing two buttons on the front panel in succession.

The drives themselves are already installed into their carriers. All you need to do is slide the carriers into the MaxNAS unit. I followed along with the Quick Start guide and was done in under a minute. The latches on the drive carriers have locks so you can lock them into the unit for extra security.

With that out of the way, I connected the AC and network cables provided. I plugged the drive into a nearby wall outlet, attached the network cable to the MaxNAS and to my switch, and then pressed the power button. Along with the typical complement of LEDs, the unit has a two-line status display on the front panel. All told, it's a nicely organized status and information center.

The installation software gives access to the drive's configuration options. Other than run the CD and install the software, I had to do absolutely nothing to get the MaxNAS up and running as a RAID 5 device. It was, in fact, the second-most labor-free installation of the three (it took a backseat to Iomega's StorCenter ix2 , but just barely). The software is browser-based; everything is laid out intuitively and accessible via pull-down menus.

In testing, the MaxNAS had very strong write credentials. It was fastest, by a sizable margin, when having data written to it. Reading from the drive wasn't as speedy. That operation was more in line with the times needed by Iomega and Promise -- the MaxNAS was slightly slower than the former and somewhat faster than the latter.

Although I could easily get by with a RAID 0 or 1 unit for a personal or even a SOHO environment, among these three the MaxNAS would have to be the choice for a SMB (or even a high-end SOHO). The high price is a bit daunting (especially if you move into the 5TB and 7,5TB units), but the additional RAID and connectivity options offset the pain somewhat.

Promise SmartStor NS2300N

Promise Technology's SmartStor NS2300N NAS unit is a do-it-ourself BYOD (Bring Your Own Disk) product that supports RAID 0 and RAID 1. This model will hold two hard disks of your choosing; there is also the four-drive model (NS4300N) available.

While the BYOD approach is a bit less convenient than units that come with hard drives, the benefit to this approach is that while the NS2300N itself will set you back anywhere from about $165 to $250 , you get to decide how much extra money you put into it in terms of the drives you buy.

To test the unit, I loaded it with two 1.5TB Seagate drives. At $140 for each drive, that's a total of about $460 for a 1.5TB SmartStor NAS RAID 1 array -- not a bad price.

Setting up the SmartStor wasn't challenging. The box includes two removable plastic carriers for the drives. I discovered it was best to ignore any screws that came with the hard disks because they didn't clear the rails inside the box. Instead, I had to use the countersunk screws Promise provides with the NAS unit. That was the only sticky point of the whole assembly.

Once I slid the carriers and their hard drives into the box, I closed the front door and connected the power and network cables at the back. (There is also a USB connector for a printer.) I plugged the cables into my network and AC outlet as required and pressed the power-on button upfront. I was greeted by a slew of green LEDs and a single beep as the drive made a place for itself on my network.

Promise's drive comes with SmartNavi software that is used to configure the SmartStor's RAID level, shared volumes, network behavior and backup regimen (if you're using it as a backup device). You can also install plug-ins that enable its iTunes server.

When you're done, you can map either the entire SmartStor or any of its shared folders to your PC. You will need some networking skills if you plan to change things around at all (like swap in new hard drives at some point) or have special circumstances. Otherwise, you're done.

Since I chose drives for capacity and not necessarily for speed, the SmartStor's test results were about what you might expect. The unit came in dead last in both reading and writing -- but not much slower than Iomega's ix2. If I were on a budget and needed a large storage capacity, this would be my choice for a personal NAS or even a low-end SOHO environment.

This story, "NAS devices offer big storage on small networks" was originally published by Computerworld.

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