Comparison: Three NAS devices offer efficient backup for small offices
- — 03 August, 2009 20:20
Network-attached storage (NAS), once only available (and affordable) for enterprises, is becoming more common for small business and even home use. And necessary — if you are looking for secure backups for your data, a single backup disk collecting data once or twice a day is no longer enough.
I looked at three NAS units that recently appeared on the market and that could suit the ambitious home or small business: Synology's DS409slim; Seagate's BlackArmor 440; and Netgear ReadyNAS NVX. None are enterprise level, but each fits a particular spot in a networking environment. They range in price from around $500 all the way up to $2,700.
How we tested
For the tests, I used a desktop system powered by an AMD Phenom 9600 quad-core processor running at 3GHz with 2GB RAM and a 500GB Western Digital Caviar Blue with 16MB cache. I used a Linksys SD2008 network switch to connect the devices.
The tests were run with a 4,661-item (8.05GB) data package consisting of a mixture of files and folders containing data, pictures, videos and music. They were first transferred from a local hard drive in a Windows 7 RC computer to the NAS device. The package was deleted from the source computer and then transferred from the NAS unit back to the computer's hard drive. A simple copy and paste was used for both operations; times were recorded manually using a Tag Heuer digital stopwatch.
Keep in mind that network traffic as well as the specifications of the hard drives used in a NAS unit will affect overall performance. Typically, the former is out of your control. That's why you usually schedule backups for after-hours in general.
In addition, the drives that you use will affect performance as well. Out of the three NAS units reviewed here, only Synology's lets you purchase the drives separately. Otherwise, you're pretty much locked into whatever drives the manufacturer believes works best with its product.
A note about RAID
RAID 5 and RAID 6 are two of the most useful data storage schemes available. Of the two, RAID 6 is demonstrably the more secure — however, while testing these drives, I elected to use RAID 5 exclusively.
Why? Because RAID 6 uses dual parity to provide data security. Whereas RAID 5's single-parity technique will allow you to rebuild your data should a drive fail, RAID 6 will let you rebuild your data should a drive fail during a rebuild of your data. The cost for that additional peace of mind is that more disk capacity will be used for parity information and write times will be slower than they are in RAID 5. As a result, in order to give the tested NAS units a chance to put their best feet forward, I opted to test using RAID 5.
In the real world, how likely are you to encounter that type of double failure? If you keep an eye on the Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.) data provided by these units' management tools at least once per month, you'll probably know well in advance of most hardware failures.
Of course, there's always the potential for catastrophic failure or for failures in areas that S.M.A.R.T. doesn't monitor. Still, in my opinion, your odds of experiencing a drive failure during a data reconstruction is probably the same as those should a meteor strike a region of the planet that is experiencing a tsunami at the same time.
Netgear ReadyNAS NVX
Two things earned Netgear's ReadyNAS NVX points in my book. First, it doesn't use a power brick, so you don't have to deal with two separate cords -- one from the box to the brick and the second from the brick to the wall outlet. (On the other hand, because it's a single cord, it's only half the length of the power cords of the other two, which could be a problem depending where you want to place the ReadyNAS.)
The second is the fact that it has a handle to make carrying the ReadyNAS easier. Why, you may ask, does it need to be easier? Because the 200.6 x 132.1 x 220.9 mm (HWD) box weighs 4.5 kg without disks installed. Since a 1TB drive weighs in at close to 680 g, a fully-loaded ReadyNAS NVX with four drives could weigh as much as 7.3 kg.
At $3,939 list, Netgear's 4TB ReadyNAS NVX is the most expensive unit in the group. (1TB and 2TB models are also available.) The unit I reviewed was stocked with four 1TB Seagate Barracuda ES.2 SATA drives that delivered 2.579GB of RAID 5 storage.
Netgear uses an X-RAID2 RAID topology. Briefly, X-RAID2 allows you to start with a single drive in the box. If you then add a second drive it becomes a RAID 1 (mirroring) system. Add a third drive (or maximize it to four), and the ReadyNAS NVX evolves into a RAID 5 construct.
This is done automatically, with the goal of providing you with as much data capacity as possible within as secure an environment as possible, all defined by the confines of the hardware the unit detects. (Once your array has been established you can also upgrade to higher capacity drives using X-RAID to rebuild your data as you go along.)
Each of the hot-swappable hard disks sit in its own tray and slides into (or is removed from) the box after opening a front door on the unit. The ReadyNAS NVX sports three USB ports that can be used for printers, external drives and even a UPS system. The unit is equipped with two Ethernet ports that feature load balancing and failover.
IE8's default security level tripped things up on my first attempt to use RAIDar, Netgear's discovery and management tool. Resetting my Internet security options to a lower level cured the problem.
RAIDar offers the usual collection of device management policies, including those for security, shares, external equipment attached via the USB ports and overall system status. Once connected to my network, the unit installed itself out of the box; RAIDar needs to be used only to fine-tune the options. A reasonable installation with an economy of customization can be done in less than five minutes.
One of the nicer options on the power saving front is the ability to have the ReadyNAS NVX shut down and power up at scheduled intervals. For example, at night it can be told to go to sleep and wake when you do, saving a few pennies in electrical costs when it does. The downside is that backups, which are typically scheduled during usage down time, won't occur if the sleep time and backup schedule conflict. Consider the possibilities before you act.
Netgear also offers an offsite backup option called ReadyNAS Vault, a remote data center that you don't need to build on your own. You get the first 30 days for free; after that, you can select options that will bring the cost down to $US5.95 per month for 5GB of storage, according to Netgear.
To be blunt, the ReadyNAS NVX is crazy fast. Writing my data package to the device took a scant 4 min., 8.1 sec., beating the Synology by a minute and a half and the Seagate by slightly more than four minutes.
And it's no slouch in the read department either. At 2 min., 47.8 sec., it put Seagate into second place by almost a minute and left Synology in the dust by about a minute and a quarter.
Upscale small to midsize businesses will find the ReadyNAS NVX to be a worthwhile weapon in the war on data protection. The cloud storage is an added plus.
The problem with the finish on Seagate's BlackArmor 440 NAS unit isn't that everyone has already done piano-black to distraction. Instead, it's the plastic "cling-on" strips used to cover the surfaces during shipping so they don't pick up smudges and fingerprints. Peeling them off was a giant pain because they cling for dear life.
On the other hand, peeling plastic from the outside of the enclosure was probably the major hurdle I faced when setting this NAS up.
The 440 seats four hard drives (there's also a 420 model that seats two drives). As delivered, they're pre-installed in their trays and nicely tucked inside the box.
You can load the BlackArmor to handle capacities of 4TB, 6TB and 8TB (using 1TB, 1.5TB and 2TB drives). My unit ($1,899 direct from Seagate) included a quartet of 1TB Barracuda 7200.11 SATA drives; that's a total of 2.62TB of storage when using it in a RAID 5 array. The drives can be hot-swapped; they're hidden behind a flip-open panel at the front for easy access.
With everything pre-installed, it's only a matter of yanking the unit out of its shipping box and setting it up on a table. It measures 160 x 205.7 x 269.2 mm and weighs 6.2 kg. Just connect it to your network and to an AC outlet and you're practically done. Although the 440 has a power-on button, the unit I reviewed powered up the first time as soon as it was plugged in and started its initialization routine. All told, it took under three minutes for it to be ready.
One thing to note is that the unit sports two LAN connectors, suitably marked "1" and "2." You can use either to connect the 440 to your network but "LAN 2" can also be used to connect the NAS unit to another NAS unit for backup purposes . There are also four USB ports for external printers or hard drives.
I ran afoul of IE8's default Internet security settings when attempting to install the discovery tool used to set up the BlackArmor. The software, which uses your browser, stalled without completing the changes to the device's name, workgroup and password. With the help of Seagate's technical support, we determined that it was the security level (accessed through IE8's Tools menu) that was blocking the tool. Once I reduced the security level I had full access.
Seagate's setup software uses a category list with pull-down sub-categories. The complete setup could have taken five or six minutes had I not known what I was doing — Seagate includes an electronic user guide to help out. As it was, I finished in about 3 minutes.
The BlackArmor 440 displayed a reasonable read time of 3 min, 42.6 sec., over 20 seconds faster than the Synology and about a minute slower than the Netgear. However, things are different when you look at write times — at a whopping 8 min., 19.3 sec., the 440 is the slowest of the three NAS units. Second place, held by Synology, is more than 2.5 minutes faster while Netgear's took slightly less than half the time of the 440.
From a price standpoint, the BlackArmor fits best in a home office or low-end small business environment where it's more important to have read access to data than quickly back it up; if you're backing up data off-hours, the slow write performance won't matter as much.
Truthfully, the real reason I wanted to get my hands on Synology's DS409slim NAS unit was because of the press release I was sent, which boasts that the DS409slim is about the same size as a coffee mug. That intrigued me, because up to that point, a 40.6 x 81.3 x 134.6 mm (WHD) Buffalo LinkStation Mini was the smallest NAS unit I'd encountered.
Apparently, they have some large coffee mugs at Synology. The DS409slim measures 104.1 x 119.4 x 142.2 mm (WHD) — a smidgen larger than the LinkStation Mini. In its defense, however, the DS409slim can accommodate four 2.5-inch drives while the LinkStation Mini can only handle two.
The DS409slim ships by itself, without any drives — you have to fill it on your own. Unfortunately, although 3.5-inch drives have reached 2TB, their 2.5-inch relatives currently top out at 500GB.
The drive supports JBOD, RAID 0, RAID1, RAID 5, RAID 5+spare and RAID 6, which means you can get 2TB of storage (roughly, before accounting for parity overhead) with four drives (1TB if you're using RAID 1). The unit has two USB ports and an eSATA port and will accommodate external printers and disk drives.
I stuffed the box with four Seagate 320GB Momentus 7200.3 drives. While not the highest capacity of the series (it goes up to 500GB), the Momentus' 7200rpm spindle speed makes it a better choice when compared to typical 5400rpm notebook drives. (Larger drives used for desktop systems have moved away from that slower spindle speed.) The drives install on trays that are supplied with DS409slim; the trays then slide into the unit on internal rails. It's pretty much a no-effort operation.
The total cost to duplicate the setup would be $500 for the DS409slim itself plus $99 each for the hard drives, based on online pricing.
As with other NAS units I've tested, the DS409slim uses a browser-based management tool called the Synology Assistant to set up the unit for access. The installation disk puts an icon for that tool on your desktop so you can access it whenever you wish. I ran into some compatibility issues under Windows 7 that initially stopped the installation, but on the second try the OS fixed the problem on its own (Windows 7 just said it had applied its own parameters to the software).
The Assistant contains nine primary menus; clicking on any one of them causes a cascade of additional options to appear. All told, the options are quite comprehensive and cover everything from shared folder creation to backup settings to how to manage peripheral devices attached to the DS409slim.
Taken in total, the bounty of options has the potential to make setting up the unit a conceptual mess. However, Synology has grouped them logically and in a clear fashion. The electronic user manual will help somewhat, but it's more of a generic tome for all of the Synology product line. As with most similar products, if you've never set up a NAS device before, it could take you as long as 20 minutes to do so. If you have, you could practically close your eyes and breeze through it.
"DIY" NAS boxes are rarely optimized. It's not because the hardware itself is lacking. Instead it's typically because we, as consumers, look for low prices when we roll our own.
For example, with the four $99 Momentus 7200.3 drives installed, the DS409slim had a respectable write time of 5 min., 38.9 sec. That was good for a second-place finish among the three NAS units I tested. Its read time of 4 min., 9.5 sec., however, was the slowest of the group. While that isn't that far away from Seagate's second place time of 3 min., 42.6 sec., it doesn't hold a candle to Netgear's 2 min., 47.8 sec.
If you want a drive that's faster and has more capacity, Seagate's 500GB Momentus 7200.4 might make a significant difference, but it would do so at a premium and a total cost approaching $1,200. A 2.5-inch hard disk may keep the power requirements and overall footprint lower, but there is a price penalty for that size and capacity when compared to its 3.5-inch counterpart.
A consumer or low-end business environment would be the best home for the Synology DS409slim both from price and performance standpoints although it could have a place in a startup midsized business.
Could Direct Attached Storage be enough?
While NAS is getting less expensive, Direct Attached Storage (DAS) drives — external hard disks attached directly to your computer — are still the kings of the cheap. If you're really trying to pinch pennies, you should be able to attach one of these external drives to one of your networked PCs and, after a few parameter changes, access it from other PCs on the network.
If you're a basic consumer looking for a single storage solution for multiple PCs, Direct Attached Storage devices are probably looking like quite an attractive option. It is, for an individual or a one-person office with multiple systems.
However, you won't get amenities like back-up timers, maximized capacity within a secure RAID variety, or drive condition information. For those features, which are important to businesses, you're going to have to pay more.
Bill O'Brien is a freelance writer who has written a half-dozen books and more than 2,000 articles on computers and technology, including Apple computers, PCs, Linux and commentary on IT hardware decisions.