Thin Client as NAS (Network Attached Storage)

I learned computer programming in high school, back in the days of punch cards and computers the size of railroad cars hidden in refrigerated rooms guarded by guys in white lab coats who would "batch" your program and tell you to come back in 3 hours when you'd  discover the program crashed because on one punch card in the 1,000 card deck you had used a semicolon instead of a colon.  Ah, those were the days!  My first personal computer was a Timex Sinclair (yes, the watch company teamed up with Sir Clive) ZX80 which came with a whopping 4K of RAM and used a standard audio cassette recorder for data storage.  This was followed in quick succession by a Commodore VIC 20, a Commodore 64 and yet another Commodore 64 purchased from what was then the world's largest retailer of personal computers, Toys 'R Us (really!).  The Commodore machines actually had floppy disk drives - I could store as much as 360K on each disk!  But then came that magic day in the early '80s when an IBM PC XT arrived at my home.  It was equipped with 64k of RAM (expandable with a full-length, very expensive card to 512k) and, wonders of wonders, a 20 megabyte Winchester hard drive.  20 megabytes!  So much storage!  How could I ever fill that?

Well, here we are in the 21st century.  My home system consists of 7 computers (4 of them are thin clients), 2 printers and a scanner, all connected with routers, wireless access points and wired switches and hubs via a gigabyte LAN.  Total storage scattered around the system is around 3 terabytes, a relatively modest amount by contemporary standards.  I routinely ship data around the LAN (and onward to my office where three computers sit on my desk, creating much confusion among my less computer-adept colleagues), stream video to my home theater, stream audio to my receiver, share documents with Mrs. ThinClient (who is absolutely helpless when it comes to things digital - she refers to my computers as "my girlfriends").  Studies have shown that 67.8% of all homes with computers have at least two connected by a LAN (other studies have shown that 78.2% of all cited studies are just made up by the authors of the articles that cite them).  With multiple computers sharing the same data, it makes sense to centralize it so it is accessible to all machines on the network.  That is the function of the NAS: Network Attached Storage.  The NAS was born in the corporate environment as the ubiquitous file server, which also ran dedicated and proprietary network server software (I understand that Novell is still around).  When Microsoft added built-in networking support to Windows 3.1.1, the lofty world of the corporate network, and all the utility it offers, came within reach of home and small-business users.  While true file servers are powerful general purpose computers that can run a variety of software, the NAS has just one function: serving up data from its hard drives on demand to any network-attached device that requests it.  It is nothing more than a relatively low-powered dedicated computer that manages data.  As recently as last year, I purchased a 350 megabyte NAS for my home LAN at the super-discounted price of $300.  But wait a second: "a relatively low-powered computer" -- that's a thin client!  Fortunately, it takes very little computing power to function as a NAS, and even the most basic "internet appliances" are up to the task.  This article describes three approaches to using a thin client as a NAS.

1.  Good

Nothing could be simpler.  Take a thin client.  Plug in a USB drive.  Attach it to the LAN.  Voila!  You've got a NAS.  All you have to do is open "My Computer" and right click on the USB drive.  In this example, it's the drive labeled Cavalry Terabyte (D:).

From the context menu that opens, select "Properties" and this is what you'll see:

Select the tab labeled "Sharing."

Click the button for "Share this folder:

Feel free to accept the default share name which, on a thin client with no other attached storage, will be D, showing up as a D: drive.  If you want to limit the number of simultaneous users, fill in a number in the "Allow this number of users" box.  Otherwise, leave it at the default of "Maximum allowed."  Next, click on the "Permission" button.

If you want to control individual users' access to this drive, you can do that here by adding users or group names and setting individual permissions for them.  If you don't, simply check the "Allow" box next to "Full Control."  Then click "Apply" and "Okay."  Click "Okay" again on the Properties window and you'll find yourself back at the My Computer window.  Now, however, you'll see a little hand under the drive icon, indicating that it is now available over the network.

And that's it -- you've got a NAS.  Just make sure that all the computer users on your LAN have access to the thin client (you can do this by right-clicking on My Computers, selecting Manage, Local Users and Groups, Users, and then setting permission as appropriate.

2.  Better

What can be better than this?  Something faster, that's what.  Except for the HP t5730, all of the HP t5000-series have 100 mbps network adapters (100baseT ethernet).  The USB 2.0 ports on the t5000 series, as well as USB 2.0 external drives have a theoretical maximum throughput of 400 mpbs, four times the bandwidth (and, because of the overhead introduced by network transfer protocols, actually well more than four times the bandwidth) that can be handled by a 100 mbps LAN (and, by way of reference, WiFi standards are 54 mbps for 801.11 G and roughly 120 mbps for draft-N).  Most recent desktop and laptop computers have gigabit network adapters (1000baseT ethernet), 10 times the speed the network adapters on the t5000-series thin clients.  Gigabit switches and routers are only a little more expensive than the older and slower 10/100 mbps versions and will work just fine with existing CAT5 network cable runs.  All you need to do to upgrade your LAN speed is plug in new routers and switches, and make sure that all your computers have gigabit NICs.  It's also very easy to upgrade a t5000-series thin client to a gigabit NIC as well.  All you need to do is get the PCI expansion module for your specific thin client from HP.  The expansion module consists of a riser for plugging into the mother board of the thin client, a new cover with extra room for a PCI card, and a slightly larger power supply to handle the additional power demands of the PCI card.  Instructions for installing the module are provided and it is a very, very simple process -- unscrew a screw or two, remove the old cover, plug the riser into the PCI slot (it can only go in one way), plug in the PCI card into the other end of the riser, slide on the new cover, screw it down, attach the small placement screw to hold the PCI card in place and you're ready to go.  The t5000-series will work just fine with any PCI gigabit NIC - no additional drivers are necessary.  Just make sure that the gigabit NIC you get is half-size or smaller (and I haven't seen a full-size PCI NIC for years), and are PCI, not PCIexpress (PCIe) or PCIx.  If you're lucky enough to have a t5730, it is already equipped with a gigabit NIC, so you don't have to do anything but enjoy the speed of your NAS.

If you want to get a little fancier, run two USB hard drives and get yourself sync software (I like GoodSync -- a powerful but easy to use program that works well on thin clients).  Set the software to automatically sync the two hard drives periodically and you'll have an automatic backup of everything on your NAS.  On my system, I have approximately 375 gigabytes of files stored.  I run a full sync every 2 hours, and it takes less then 10 minutes though, obviously, more if I've added a lot of software to the NAS.

3.  Best

It's back to the numbers again.  Your thin client NAS can now move data around at the full speed of the LAN, 1000 mbps.  However, as noted before, USB 2.0 ports are limited to a bandwidth of only 400 mpbs, roughly 40% of the maximum throughput of a gigabit LAN.  We can do better than that, can't we.  Well, we can, but it's going to take an HP t5730 to do it.  That's because we need yet another PCI card and t5000-series thin clients have only a single PCI slot which is already occupied by the gigabit NIC card.  The HP t5730, however, already has a built-in gigabit NIC, leaving the PCI slot free for a different card, and that card is an eSATA PCI card.  Hard drives were originally parallel devices, meaning that each byte of data, composed of 8, 16 or 32 bits, was sent down parallel wires, one bit in each wire.  The problem with this approach is that timing is critical - each bit must arrive exactly at the same time as its brother bits that make up a single byte or the data is corrupted.  Electrical interference, minute resistance changes in the wires, and component drift could all affect the timing of the bits.  The net result was to put a practical limit on maximum speed that data from the hard drive could be transferred to the computer. 

SATA drives (Serial ATA) send each bit, one-at-a-time, over a single wire to the computer where they can be reassembled in consecutive order into a data byte.  Because timing is no longer critical - the computer just grabs each bit as it arrives - the drives can transfer data much faster.  How much faster?   The older ATA/PATA/ATAPI standard maxed out at 133 mpbs.  Modern SATA drives can achieve 3 gbps - 3 gigabits per second.  Now that's fast.  Recently, external SATA devices have made their appearance (called, not surprisingly, eSATA drives).  These, too, can transfer data at up to 3 gbps.  So, do you want to goose up your thin client NAS?  Just get an eSATA PCIe card.  Unfortunately, this is a little more complicated than it sounds.  eSATA PCIe cards come in a bewildering range of configurations.  First of all, cheaper cards only run at 1.5 gpbs.  Yes, that's fast, but even speedier LANs are just around the corner so why invest in technology that will be obsolete in a year or two?  Next, most eSATA cards are PCIe, and not PCI, cards.  The HP t5730 has a slot that will support either PCI or PCIet.  Howver, all PCIe slots are not created equal.  eSATA cards communicate to the motherboard through channels, either 1, 4, 8 or 16 channels.  eSATA cards are specified by the number of channels they require, e.g. PCIe 4x for a 4-channel board or PCIe 16x for a 16-channel board.  The t5730, however, being a limited thin client can only support PCIe 1x.  Frankly, it is not easy to find a PCIe 1x multiple port external eSATA card.  Wait, you say.  What's this about multiple ports?  Just like USB and Firewire cards, you can get eSATA cards that will support more than one external device.  Why get a multiple port card?  Well, two good reasons.  First the obvious: want more storage?  Just plug in another eSATA drive.  However, the second reason is more compelling.  RAID is hard drive protocol that makes data more efficient and more secure by spreading it across multiple drives.  The simplest form of RAID simply mirrors the data from one drive to another, essentially making a real-time backup.  This is called RAID 1 and provides data security.  RAID 0 "stripes" data across two drives.  It doesn't add security, but it does increase efficiency and adds speed.  RAID 5 works with 3 or more drives and combines striping with separate storage of additional data that allows corrupted data on any single drive to be fixed.  Most corporate LAN installations use RAID 5.  With a multiport eSATA drive it is, in theory, possible to run a full 4-drive RAID 5 system.  I was able to find a well-reviewed card that satisfied all these requirements: 4-port, 3.0 gbps transfers, PCIe 1x.  The Highpoint RocketRAID 2304 fits the bill.  It is, however, not cheap.  The best price I found was around $150.  For external eSATA drives, I like the Cavalry 1 terabyte USB/eSATA external drive which can occasionally be found on sale at buy.com for as little as $149.00.

Now the next problem: XPe will not support the RocketRAID controller.  The only way around this that I found was to run full XP Pro on the t5730.  I'll do a separate article on running full XP Pro on a thin client.  The short version for here is that XP Pro requires approximately 6 gigabytes of storage, far more than the 512k - 1 gigabyte of flash RAM that comes with thin clients.  The simple solution is to install an 8 gigabyte flash RAM.  You can get one that is pin-to-pin compatible from Transcend.  Once full XP Pro is installed, the RocketRAID card installs easily and it takes no time at all to set up the RAID system.