The Plot Thins: Thin Servers in 2000
January 2000 |
The Thin Server world has certainly come into its own in the last year. Many vendors, including some of the major drive manufacturers, now tout the value of a thin server/network-attached storage (NAS) approach. They highlight the strengths of an appliance approach to adding CD or DVD-ROM storage or adding RAID systems to a network.
Three companies still specialize in providing thin servers to the general IT market: Axis Communications, TenXpert Technologies (formerly TenX Technologies), and Microtest. Compared to the more densely populated scene of a few years ago, where more companies were vying for pieces of a smaller pie, the plot has certainly grown thinner. But as far as power and versatility go--from ever-larger hard-drive caches to recording and DVD support--the pickins surely aren't, as a thorough examination of these three slim servers amply demonstrates.
The first new system we looked at is Microtest's DiscZerver VT, an external thin server that supports up to seven SCSI-2 drives or changers.
I admit I was pleasantly surprised in testing this system out. Since the unit has no LCD screen, I expected to find myself struggling to get my Novell client workstation to recognize the DiscZerver. I was delighted to find that the instructions in the manual actually worked, and after I typed in a standard URL, my browser not only located the system but brought up the configuration utility as promised. Now that's a welcome change from similar systems that have left me feeling like I'm playing hide and seek with the IP address.
This small, book-like unit is unobtrusive, with only four LEDs on the front to indicate its operation. We attached a 10BaseT network to it running NetWare 5.0. We then hooked up a Yamaha CD-R400 drive to it and powered it up.
A Surprising Performer
There's been a lot of discussion about the performance hit users allegedly take when they opt for thin servers instead of more traditional network configurations. Since these systems use a low-cost chipset, some question how good a thin server can be in retrieving data. In our research, we find that administrators do want performance. But they also want two other features: reliability and manageability. Without these two, a great performer isn't worth the investment. And on this count, the DiscZerver definitely delivers.
That said, in looking at the DiscZerver, we find the little guy pretty outstanding for a general-purpose thin server. We ran it through its paces, reading both from the internal cache and from the CD-ROM drive directly. We tested the system's transfer rates for files of two sizes: 5MB and 13MB. The CD-ROM drive's transfer rate for the 5MB file was 8Mbps; for the 13MB file, 422KB/sec. The hard drive cache clocked in at 7.7Mbps for the 5MB file, and 317KB/sec for the 13MB behemoth. Tests were run on an unburdened 10BaseT network from a Windows 95 workstation.
These numbers represent about the best-case scenario for the DiscZerver, and they do show some solid throughput. The VT is quite capable of flooding a 10BaseT connection when accessing files under 5MB.
In another test, we inserted a test CD-ROM with 35MB of content into the unit to find out how fast the content would become available from the internal hard drive. Caching speeds are, of course, dependent on the speed of the CD or DVD-ROM drive itself. Our Yamaha unit delivered the 35MB contents of our test CD-ROM to the DiscZerver in 2 minutes, 30 seconds. This was measured from the time we inserted the disc until it was available on the network.
User Security: To Protect and Zerve
The VT supports up to 250 uniquely defined users, and the 32MB of onboard RAM means about 8 to 10 of these users should be able to access the unit simultaneously. Realistically, this 250-user license serves more for full integration with NT Domain services and Novell's NDS (as a Bindery server) than a strict limit on the DiscZerver itself.
We commend Microtest for its continued support of multiple security schemas, an important feature given the prevalence of heterogeneous networks in today's connected computing environments. So support for the de facto directory service, NDS, needs to go hand in hand with continued support for domain services.
Compatibility: A Bridge Too Far?
The DiscZerver handled ISO9660 discs without a hitch--including CD-ROM and CD-R. However, UDF support isn't here yet (and is spotty in other thin servers as well.) So reading CD-RW discs, not closed as ISO, is out.
DVD support was fine, if limited to those discs with UDF Bridge formatting. Since almost all DVD-Video and DVD-ROM discs do use the UDF Bridge format, this should be no problem for most users. (DVD-RAM, which is UDF by definition, is not supported, and we can assume it won't support DVD+RW if the current model is still in use in mid-2001 when the format finally debuts.)
We had to look into the fine print to see that the system supports DVD-ROM caching only up to 2GB or less. (It would be nice if we could pick which 2GB that is.) In all fairness, we should point out that the Axis StorPoint limits the size of DVD-ROM caching as well.
As for network support, we found the unit as polylingual as any, with NT (SMB), NetWare (NCP), Unix (NFS), OS/2 (SMB), Web (HTTP), and Macintosh (AFP). We consider the latter a significant enhancement now that Apple is growing as a player again.
Write Your Own
The current DiscZerver 3.0 also supports writing your own CD-Rs across the network. This capability, which we have also seen in the TenXpert system, is very useful for archiving data from workstations without CD-R capability of their own. The unit supports a number of CD-R drives (including a couple of RW-capable recorders as well, although only when used as CD-R burners). These include Yamaha, Plextor, HP, and Smart and Friendly systems.
DiscZerving Made Easy?
When it comes to software, Microtest offers an unsurpassed set of management tools for the DiscZerver. In addition to the Web-based Administrator ToolBox, Microtest also offers LaunchPro, a bundled management, application launcher, and statistics and metering program. Finally, there's the workstation-based EazyImage program for copying local CDs and DVDs to the network cache. All were intuitive and easy to use, even surprisingly so.
We also commend Microtest on one of the finest manuals of any product ever reviewed in these pages. It provided the right level of hand-holding almost all the way through the process of installing and using the VT.
If there is a drawback to the unit, it is in the lack of an LCD screen. This lack on the DiscZerver limits you when looking for diagnostic information, such as a SCSI bus error or drive failure. (The Axis E100 also lacks this feature. Only the TenXpert unit offers such a screen.) Although some diagnostic information is available in the browser-based tool, this won't help if the problem is in the connection. Having a screen serves as a final step before resorting to tech support.
BRING IN THE TENXPERTS
All things being equal, it sure was nice to run the new TenXpert as the host for the Cygnet DVD 100 jukebox. Compared with the hassles we had creating the NT host in the Cygnet system's October review [pp. 57-61--Ed.], the TenXpert support was a dream.
Recording is not the only distinguishing feature of the TenXpert, which also provides solid performance for reading both CD and DVD discs off the jukebox.
Granted, there's no file rewritability for DVD-RAM media in the TenXpert. (Your only choices are to write it once, as if it were a 2.6GB CD-R, or to erase the whole and start over.) But for archiving I can almost live with that. What I don't think most can live with is the lugubrious recording speeds on the Cygnet's Hitachi drives.
TenXpert warned me that I might see sub-100KB/sec recording speeds with the Hitachis, and I did. When I did my first review on the box using NT as a host, I didn't encounter lightning speed either--it typically registered about 200KB/sec. This time, it wavered from 80 to 150KB/sec, depending on whether I hassled the TenXpert to do a read in the meantime (sometimes it slowed down even if I didn't.)
This slow speed makes this particular thin server/jukebox combination a tough bottleneck for network storage for more than a few users (after all, a full 2.6GB disc would take four hours to record). Compare this with one or two hours with a faster Toshiba-equipped system, and you get an idea of the difference we are talking about.
However, the $7,800 price tag of a Cygnet DVD 100 is almost $3,000 less than the comparable-in-capacity NSM 4000--which sells for around $10,795--so it might be a worthwhile tradeoff. Finally, I should also say that with an internal write cache of 18 to 36GB, the TenXpert can hold onto that recording data for a while and thus mask the overall recording speed from some end-users. But not a lot of them.
Recording is not the only distinguishing feature of the TenXpert, which also provides solid performance for reading both CD and DVD discs off the jukebox. Using its internal read cache, it can also be a good partner on the network, if not quite as fast as the Axis-equipped Excelerator.
Our test TenXpert came equipped with a Seagate Barracuda drive with 18GB capacity. We needed to perform a firmware upgrade to the system after we received it before beginning our tests. (This upgrade would improve handling of the two DVD-RAM drives on the Cygnet box.)
I approached the product with much the same anxiety level I had for the DiscZerver, expecting the TenXpert firmware upgrade process to be both tough and replete with errors. Neither assumption proved true. Just a simple file copy and a reboot did the trick. TenXpert tells me that even if the upgrade failed to "take," I could still roll the system back to a state where I could try again.
R and RAM-Making:
WORM by Turns
If you want to use the TenXpert with the Cygnet DVD 100 as we tested here, you will need a third-party recording package. TenXpert recommends NTI's CD-Maker Pro. In the past, you could use any CD mastering package with the TenXpert so long as it allowed you to save the image file to the TenXpert's drive letter. You can still do that with this latest version, but if you want to record to DVD-RAM, you'll need the CD-Maker software.
Why? Because only CD-Maker apparently lets you arbitrarily set the size of the recorded image file. Yes, it does give you a bold warning that you are exceeding the 650MB limit of CD-R recording. But once you click OK on the warning box, you can proceed to record up to 2.4GB of data onto the DVD-RAM media (the other .2GB are needed by the file system). Other packages simply don't let you specify an image larger than 650MB. While you could theoretically record only 650MB on a single DVD-RAM disc, it would be a waste of capacity and money, given that the discs cost roughly $15 more than a typical CD-R blank.
CD-Maker Pro is a $50 buy from one of many online vendors. TenXpert didn't bundle it with its system, apparently as a way to save money for those who aren't going to use DVD-RAM yet.
Like a Smart Storage host, the TenXpert treats DVD-RAM like an erasable WORM drive. If you want to write something to an existing DVD-RAM disc, you'll have to erase the entire disc first, then start over with a new image file.
That's because the TenXpert records using ISO9660 and not UDF on the disc. As the company explained it, getting the system to support UDF is a significantly "non-trivial" exercise. Also, performance suffers even more trying to cope with UDF. On the plus side, the DVD-RAM is extractable from the box and readable in another DVD-RAM drive on a standalone computer, for example, something which is not do-able with the SmartStorage-recorded discs.
The TenXpert pulled data off CD-ROMs at about 740 to 750KB/sec using a single test workstation to access the device. We didn't use the onboard caching capability once again in order to view the worst-case performance of the device.
We already discussed the apparent slowness of the Hitachi DVD-RAM drives in the Cygnet box. The company says that Toshiba drives perform two to three times better with their thin server, but we weren't able to test that.
TenXpert is working hard to update the software management tools for its thin server. Right now, the system has one Windows-based console for specific read-write tasks (you can of course access the CD-ROM and DVD volumes via Windows Explorer). This tool has changed little since we first saw it a year and a half ago. In fact, the only major difference that I could see between the old and new is the added support for DVD-RAM media.
TenXpert has promised a revision of this venerable XpertView management software, but the current interface is more than dated. It resembles in concept the type of gauge you would find in a 1956 Checker cab. Effective, yes. But certainly not elegant.
There is also a rudimentary Web capability consisting of a single INDEX. HTM page at the root of the TenXpert directory. This provides options for disc access and viewing configuration information. In our test, the disc access part didn't work, although we could view the configuration information.
Considering the positively elegant Web tool included with the Excelerator, and the general trend to make all network management browser-enabled, a new Web tool for the TenXpert is overdue.
As we mentioned earlier in our look at Microtest, a major plus for the TenXpert is its LCD front-panel screen. This screen is also replicated using the Windows-based XpertView software. This is key for MIS in diagnosing and troubleshooting.
AN AXIS STORPOINT CASE IN POINT: THE EXCELLENT EXCELERATOR
Having gotten my feet wet and my anxieties assuaged with the relatively painless installation experiences of the Microtest VT and TenXpert thin servers, I proceeded to the Axis component of the testing process anticipating a third smooth sail. Despite early concerns about setup hassles, I had been rewarded with a very simple process and found myself ably guided by complete manuals. So you can understand how previous experience had emboldened me to try running the Axis StorPoint-equipped DVD tower from Excel with only its manual at hand.
Despite two hours of effort, I could not get the Axis unit to give me rights to configure it. The manual itself assumes too much ability on the part of users. The online help was also far too brief, giving only vague hints about why I couldn't get rights to the server. Although I was logged in as a system administrator to the network, and as the user ADMINISTRATOR on the Axis StorPoint, the unit would still not provide me access. (Turned out the user name was SUPERVISOR and it had a preexisting undocumented password.)
In all fairness, the VOLUMES directory came up the first time I powered on the Excelerator. That indicated that I now had online access to all the titles in the tower. However, given my frustration with administrator access, I strongly recommend then to follow the instructions on the top of the Excel machine which say, "When you are ready to connect your Tower to the network, please call Technical Support."
A Good Read
The Excelerator is a CD/DVD read-only system. The tower we tested included two Pioneer DVD-303 readers and four DR-U16S CD-ROM readers. All are Ultra SCSI drives (20MB/sec top transfer rate), so the SCSI bus shouldn't produce a bottleneck for the maximum read speeds of all six optical drives. The seventh device is the internal caching hard drive.
As a read-only system, the Excelerator's Axis StorPoint thin server doesn't offer the same flexibility as does the Microtest for recording CD-Rs or the TenXpert for handling DVD-RAM. Rather than viewing the Excelerator as a storage component, it may be better to see it as a network data resource supplying data but not serving as a destination device.
Read performance for the unit was the best of the bunch. In a single-user test, the Excelerator delivered 850KB/sec over 10BaseT to the workstation from a 5MB CD-ROM file. This was 10 percent better than the TenXpert. (Our tests are designed to bypass the caching capability of the system in order to see what the uncached read speed is. Once a title is cached to the server's hard disk, we anticipate full network speed from the Ultra SCSI drive.)
From DVD-ROM, performance was slower, with data coming across at 600KB/sec from a 12MB file.
Reads Like a Novell:
An unrivaled highlight of the Excelerator is its complete integration with Novell Directory Services (NDS). With more and more enterprises turning to directory services for managing the increasing complexity of their networks, this full support makes the Excelerator an excellent add-on to the Novell environment.
That's not to say the others can't play in a Novell system; both the Microtest and the TenXpert function as emulators of the older Novell 3.x servers, and therefore are accessible from NetWare 4 and 5 users. But they can't be managed as well from Novell's administrator tools as the Excelerator--both for security and for monitoring and maintenance. The Excelerator literally becomes a NetWare server to NDS. (Microtest has announced NDS support in its newest version.)
It may be argued that the simple and often easy-to-use security tools provided with other thin servers are adequate for handling optical storage. Since we are dealing with Read-Only discs, security only has to be nominal for most networks.
This approach, however, presents a major hurdle to MIS--another tool to learn and another skill set to acquire. Many software-buying decisions today are made because a tool supports the user's familiar operating system, rather than being the best tool performance-wise. So by leveraging NDS so effectively, the Excelerator makes a persuasive argument for Novell users.
A TRIO STILL IN THE
THIN OF IT
CD-ROM and DVD-ROM content is not going away, so the need for network access to this content is bound to remain with us for quite some time as well. While other NAS vendors appear to be focusing on higher-end RAID solutions, Microtest has maintained a solid lead in making optical content available online. The company's clean, well-thought-through tools and manuals give it a significant edge as a single source over competing products in this category. We hope the DiscZerver VT is only the latest word in access appliances from Microtest, not the last.
If you are looking for a general-purpose thin server with support for jukeboxes, then TenXpert's self-named server is the choice. In fact, it is the only choice for jukeboxes--the other slim servers support only towers or external SCSI drives. It is also the only one currently supporting a type of DVD-RAM recording. As we have said in the past, the TenXpert isn't the prettiest, and the software isn't elegant. But like the Checker Marathon taxis of old, when you want a job done, expect the TenXpert to do it.
Finally, if you need support for a large number of users hitting your optical storage subsystem, then an Axis-equipped system like the Excel Excelerator is the answer. Some users will prefer Microtest's broader software bundle, but others will want a simple, straightforward storage system like the Axis. It includes a good browser-based device management tool and a nifty StorPoint Disco title-management tool to handle most user needs. The Excelerator itself is clearly well-crafted from a vendor eager to establish itself as the key player in today's emergent DVD tower market.
Long ago, in 1992, Ornetix Network Products, an Israeli startup, introduced the concept of the thin server with its SerView software. The company reached its pinnacle of development in 1997, with the introduction of the HyperLinq self-contained thin server and CD Commander management software. At that point, Ornetix faced a choice: become a hardware vendor offering towers, jukeboxes, and other thin-server appliances, or remain a strictly thin- server specialist.
Unfortunately, the window of opportunity closed on Ornetix before it made its future path clear to the market. At that point, competitors such as Microtest and Axis had answered the call for thin servers, leaving little for Ornetix to do but regroup and relaunch.
The inheritor of this pioneering technology is StorLogic, a Florida-based company with an announced strategy of creating thin servers based on Windows NT. As a differentiator, StorLogic couldn't have selected a more distinct platform. Other vendors have for the most part chosen a Unix or Linux derivative for their thin-server technologies. A few have created their own unique OSs to handle I/O on the thin server. None has chosen the NT platform as yet.
It remains to be seen if StorLogic can leverage the unwieldy NT code into an effective server solution. Still, few would have bet on its antecedent's SerView product in 1992 to change an industry either.
Configurations and Capabilities
Microtest DiscZerver VT External
7-disc (tower) $800; 14-disc $1800; 28-disc $2400; 49-disc $2700
TenXpert Standalone DVD/CD-ROM File Server
DVD-RAM: Yes (if ISO9660)
DVD-RAM: Yes (if ISO9660)
8-disc (tower) $2995; 18-disc $3995; 36-disc $9995
Excel Computer Excelerator Plus-S
30-disc (jukebox) $4,120; 50-disc $4,790; 70-disc $5,770
Companies Mentioned in This Article
Axis Communications Inc.
100 Apollo Drive, Chelmsford, MA 01824; 800/444-2947, 978/614-2000; Fax 978/614-2100; email: email@example.com; http://www.axis.com
3330 Earhart Drive #212, Carrollton, TX 75006; 800/995-1014, 972/980-7098; email: firstname.lastname@example.org; Fax 972-980-0375; http://www.excelcdrom.com
4747 North 22nd Street, Phoenix, AZ 85016-4708; 800/526-9675, 602/952-6400; Fax 602/952-6401; email: email@example.com; http://www.microtest.com
498 Palm Springs Drive, Suite 100; Altamonte Springs, FL 32701;
877/786-7564, 407/261-8977; Fax 407/261-8983; email: firstname.lastname@example.org;
13091 Pond Springs Rd., Austin, TX 78729; 800-922-9050; Fax 512/918-9182; emal: email@example.com;
NETWORKOBSERVER columnist David Doering (firstname.lastname@example.org), an EMedia contributing editor, is also senior analyst with TechVoice Inc., an Orem, Utah-based consultancy.
Comments? Email us at email@example.com.