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-------------------------------------------------------------- This story was printed from ZDNet Australia. --------------------------------------------------------------
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Getting attached to your network August 07, 2003 URL: http://www.zdnet.com.au/reviews/hardware/storage/soa/Getting-attached-to-your-network/0,139023427,120271600,00.htm
 By now the benefits of network attached storage (NAS) over direct attached storage are fairly well known. We review four NAS appliances designed to ease the storage load on your servers and the workload on your admins. 
The competition for your storage dollars is about to get fierce. EMC, a longtime leader in corporate storage, is being hammered on all sides from competitors, and the pressure is only going to get worse. Unless your organisation has a compelling need to make additional storage purchases today, your best bet is to wait and see how the storage market shakes out over the next six months. To be prepared for the new storage market, it's time to consider how new developments in storage technologies will affect your organisation. The need for a strategy Even after loading up a desktop with all the bells and whistles of the latest Microsoft OS and productivity applications, there's usually half of a 20GB hard drive left over. And since many newer applications are deployed as Web applications, the need for local storage further decreases. However, the rise in Web-based applications does stimulate the need for more staged or centralised storage. But unless they're doing advanced data analysis or video editing, most corporate users will never need 80GB hard drives. Many companies use a hard drive's excess space to store a mirror image of the base configuration to regenerate a user's desktop configuration remotely in the case of a virus attack or a software installation gone awry. PCs with important data can be mirrored easily and cheaply with existing hardware. Advanced desktop operating systems like Microsoft Windows 2000 and XP support mirrored hard drives without using specialised hardware, which makes it simple to create systems that will survive hardware problems. Putting cheaper storage to good use Windows Powered NAS lets companies consolidate multiple file servers into a single solution, resulting in significant cost reductions. It also increases manageability by enabling policy-based management of storage resources. As OEMs begin rolling out solutions based on this technology, departmental NAS devices can become part of an organisation's overall managed storage strategy. Microsoft isn't the only company interested in this space. Several manufacturers are developing Linux-based shared storage solutions based on either NFS or the SAMBA file system (making them compatible with Windows-based networks). Small businesses and remote offices will also benefit from the inevitable bundling of storage as well as wireless connectivity, router and switch technology, and Internet communication standards like PPTP and IPSec. By the end of the year, several companies will be offering remotely manageable hardware solutions that integrate firewall, router, wireless access point, Web server, and NAS. The battle for the data centreAs online storage keeps getting cheaper, tape backup solutions become less appealing because of the time required to recover from tape and the sequential nature of tape storage. Plus, the cost per gigabyte of tape storage is staying relatively constant, while the cost per gigabyte of hard drives keeps dropping. As connectivity's cost decreases and its reliability increases, more companies will consider consolidating storage in the data centre. Web applications and data warehousing systems both contribute to the consolidation trend. Large companies are also beginning to recognise that heterogeneous system support for storage is mandatory. As corporations deploy storage area networks (SANs) in their data centres, they're looking for solutions that support data storage from UNIX, mainframe operating systems, and Windows-based systems on the same SAN. When companies like Dell enter the market in full force later this year (Dell is actually using EMC technology to create its own devices to compete with EMC), the cost per gigabyte of enterprise storage will decrease for everyone. Even companies like Cisco—traditionally a communications company—are looking at the enterprise storage market as a potential source of new revenue. In fact, EMC technically isn't even the top dog anymore—HP/Compaq is. With its recent acquisition of Compaq, HP is now the top provider of storage solutions in the industry with a 25 percent market share, compared with 17 percent for EMC. Of course, what all the players in the storage market must figure out is how to move from the commodity hardware business into the business of providing management software for disparate SANs. The future is software As you develop and create your storage strategy, you need to realise that storage solutions are following a path similar to that of the personal computer. As the cost of the hardware declines, the cost of the software and personnel to maintain and manage it becomes much larger. Lots of options AnexTEK AccuSTOR NS110 In some respects the 1RU NS110 is of similar design to the Quantum; the drive bays cannot be accessed without first removing the front facia entirely. The front facia can only be released using a key to prevent prying fingers, but let's face it, in most cases the unit should be well away from the public in any case.
We have to say right from the outset that we are not fans of the NS110's drive cradles. Initially the unit was supplied without any drives so when they arrived we had to install them in the cradles, which is—to say the least—rather fiddly. OK, this is not something you're going to have to do very often, but it is not particularly elegant, and neither is the actually operation of the cradles. In addition to the keylock, the front panel includes a power switch, recessed reset switch and status LEDs for the two 10/100 LAN ports, system operation and hard drive activity. The rear of the unit is pretty sparse with the two LAN ports and a serial port, although there is provision for an external SCSI connector. The motherboard is a tiny unit with the NAS OS stored in flash memory. In the unit we reviewed, it accommodated an 850MHz Celeron CPU and its single memory slot a 128MB SDRAM module. There is provision on the motherboard, using a MiniPCI connector, for a SCSI card; this is not yet available in Australia. The system included a single power supply but there is provision for dual power supplies to be fitted, however this does not appear to be a simple upgrade option. The CPU is fitted with its own cooling fan and there is a second located in the case to cool the CPU should the first fail. There is a bank of four fans to cool the drive bays and the power supply has a pair of small fans. Documentation was limited to the PDF files on the supplied CD, which was relatively complete, but included some less than perfect English sentence structure. The Web interface for the NAS was a little clunky when compared to the other vendors' more polished products, but was nevertheless complete and quite easy to use. In general the NS110 had the lowest performance of all the NAS tested. This is hardly surprising given its relatively modest specifications when compared to the other units, for example it had the slowest CPU, least memory and only two IDE channels shared amongst potentially four drives.
Compaq StorageWorks NAS B2000
The Compaq is certainly the largest unit we tested, at 2RU high and almost 70cm deep, but it's also easily the best in terms of workmanship. The front panel is dominated by six drive bays. The configuration we tested used five of these bays; a mirrored pair of 18GB drives for the OS and three 72GB RAID 5 drives for data. The server can be equipped with a fourth drive for a total of 291.2GB raw storage. In addition, StorageWorks 4300 external drive enclosures can be connected for a total of 126 72GB drives, or around 9TB of storage.
The removable drive cradles are large and substantial units but a little care must be taken when inserting the cradle that it actually seats properly; it is possible to latch the cradle in place when it's still not quite in home position. Also on the front panel are a slimline floppy drive and CD ROM drive, power switch, and status LEDs for the network and system. Each drive cradle has integrated drive status LEDs. There are Unit ID (UID) indicators on both the front and rear of the unit which can be toggled from the Web admin console so you can easily locate the relevant unit in a large stack. Located at the rear is a pair of Ethernet ports, two USB ports, two PS/2 ports, a serial port, and an external SCSI connector. There are also two pairs of status LEDs for the hot-swappable PCI64 expansion slots. The NAS is fitted with a Remote Insight Lights-Out board that is independently powered and includes its own processor with keyboard, VGA, and LAN connectors so it can be locally or remotely administered. This allows the administrator to remotely power down or power up the NAS. Redundancy is not something Compaq has taken lightly in the design of the B2000: there is provision for a second 1.4GHz Pentium III CPU, it has a pair of hot-swap power supplies and there are eight cooling fans excluding those in the power supplies. The cooling fans are generally paired in case of failure and if one fails a status LED on the top glows amber; they are a user replaceable item. The B2000 even has four spare memory slots when configured with 512MB of ECC SDRAM. The installation kit is very complete with a rear "cable tidy’, and heavy-duty sliding rack mounts (given the unit's weight, they are definitely necessary). The documentation is primarily PDF-based although the large foldout "Quick Reference and Rack Installation Guide’ is superb. The Compaq was one of two units we tested to run Windows 2000 internally (the other two running embedded Linux), and uses the standard Microsoft Web interface. The interface is clean and simple to use with most of the functions maintaining a similar look and feel in terms of layout and functionality. Of the three NAS units we looked it without gigabit Ethernet capability, the Compaq was in general the fastest, particularly in the PostMark benchmark. It's a shame HP didn't send us the $500 gigabit Ethernet card, because we feel it could have performed a lot better with this option installed.
Iomega NAS 405M
The Iomega unit has a moderately deep 1RU form factor. The front panel styling tends to the futuristic and includes status LEDs for the four drive bays, two LAN interfaces, and system. The four drive cradles, although not quite as smooth in operation as the Quantum, are nevertheless very good with positive feedback when seated. The cradles are fitted with IDE drives but the cradle's end connector resembles a high density SCSI connector.
At the rear of the unit you will find two 10/100 Ethernet ports, a serial port, PS/2 port, VGA port, and SCSI 3 port. A PCI-64 Adaptec 29160LP SCSI adaptor card takes up the unit's internal PCI slot—which is only a 32-bit port. The Iomega's motherboard also includes a pair of USB ports and a PS/2 mouse port, but these are simply blocked by not including the relevant cut-out at the rear of the case. The motherboard was fitted with a 1GHz Pentium III CPU, and a pair of 256MB SDRAM modules occupied the two memory slots. There is a single power supply and no provision for a second; cooling fans are quite sparse as well. The power supply has a small cooling fan and a larger unit cools the CPU via a metal deflector but there is no direct cooling of the drive bays. As a result, we found during operation that the unit tended to become hotter than the other three. Setting up the system was relatively easy, although the large "Setting up your System" sheet was very rudimentary when compared to some of the other vendors', notably Compaq. The bulk of the documentation, which is actually quite good, is in PDF format. In common with the Compaq NAS, the Iomega is "powered by Windows 2000" and utilises the Microsoft Web Interface. The Iomega features a reasonably fast CPU and a healthy 512MB of memory, coupled with four quite fast IDE drives, each with its own dedicated IDE channel. The medium and large file copy results reflect this and in these tests, the Iomega was the fastest of the units equipped with 100Mbps Ethernet. Inexplicably, it was the slowest of the NAS units in the multiple small file copy test and only marginally faster than the AnexTEK in PostMark.
Snap Appliance Guardian 4400 Snap Appliance is the division of Quantum that recently spun off to focus on NAS appliances. As such, you'll notice a fair bit of Quantum branding on the device and Web interface—at least for the time being.
The Guardian is a 1RU unit with quite a small footprint; it's only marginally deeper than it is wide. The charcoal grey front panel includes status LED's for each of the four drive bays, there are also status LED's for the two network ports as well as power and system status LEDs. At the rear you will find a serial port, a pair of USB ports, and a pair of 10/100/1000 Ethernet ports. There is also an Ultra SCSI 160 port located at the rear, that is provided by an internal PCI-64 Adaptec 29160LP card. A 1.266GHz Pentium III processor with 512MB of ECC SDRAM powers the system; there is also a free memory slot for additional RAM. The single power supply (there is no provision for a second) has a pair of cooling fans while a very large fan cools the CPU. To access the hard drives, the front facia must be removed—a very simple task. The drive cradles have a very smooth locking action, one of the best we have seen. The supplied Quick Start Guide, while pretty basic, was nevertheless enough to get the unit up and running and an IP address assigned. The User CD includes a fairly basic utility called NASManager, which enables you to locate the NAS, get information such as current configuration and BIOS version, set the IP address, shutdown or reboot the NAS, or launch the Web Browser administration page. Web administration is a very complete management tool and about as easy to use as you could get. The Snap Appliance was the only NAS configured with gigabit Ethernet, and in the performance testing this bestowed a significant advantage. In every test the Snap Appliance was faster than the other three NAS units; at times more than four times faster.
* External storage may be attached using the installed SCSI card
How we testedWe assessed each NAS device for ease of set-up, paying particular attention to the following:
The Test Environment
The Linux box was used to assault the NAS under test using Postmark which is described below. The gigabit Ethernet NIC was included to ensure the maximum bandwidth when firing multiple files at the NAS. The Windows box was used to simulate a typical user on a 100TX LAN saving and retrieving files of various sizes to and from the NAS. Windows File Copy Tests
Postmark Benchmark The incidence of each transaction type and its affected files are chosen randomly to minimise the influence of file system caching, file read ahead, and disk level caching and track buffering. Postmark was run from a Red Hat Linux 7.2 client using Samba (SMB) with 1000 initial files sized between 500 bytes and 500KB with a total of 10,000 transactions. Read and write throughput scores were recorded. Benchmark results Sample scenarioCompany: ALS Corporation This company wants to migrate users’ home directories and e-mail storage to a central NAS repository. Approximate budget: $25,000 Requires: One NAS appliance with at least 200GB raw storage space, Gigabit Ethernet (copper) connection preferred. Concerns: Performance is an issue, but ongoing management costs are a bigger concern. The ability to connect with multiple operating systems is also a consideration. Expansion potential—either within the unit or by daisy-chaining several units—will also be taken into account. Best Solution: Compaq StorageWorks B2000 When considering the scenario, two NAS appliances stand out: the Snap Appliance 4400 and the Compaq StorageWorks B2000. The Snap because it was blindingly fast, primarily because it was equipped with Gigabit Ethernet. The Compaq because of extraordinary feature set and expansion potential. We tend to lean towards the Compaq, even though it is almost twice the price of the Quantum given that if fitted with a $500 Compaq gigabit Ethernet card, it would potentially be just as fast or faster. Editor's ChoiceCompaq StorageWorks B2000
There's no point in buying a product that's just going to be adequate for your needs right now, especially if your needs are likely to expand. And let's face it, with storage, your needs will always expand. That's why we think the Compaq is the best NAS appliance we reviewed, even if it's also the most expensive. Its expandability, modularity, and built-in redundancy make it an excellent choice to serve your storage needs well into the future. Subscribe now to Australian Technology & Business magazine.
About RMIT Test Labs
RMIT IT Test Labs is an independent testing institution based in Melbourne, Victoria, performing IT product testing for clients such as IBM, Coles-Myer, and a wide variety of government bodies. In the Labs’ testing for Technology & Business, they are in direct contact with the clients supplying products. Their findings are their own—only the specifications of the products to be tested are provided by the magazine. For more information on RMIT, please contact the Lab Manager, Steven Turvey.
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