Reader's Voice: Building Your Own File Server


Perhaps you've decided to take the plunge and build your own personal file server. But why bother with dedicated storage hardware when the desktop hard drives in your PC already offer up to 2 TB of capacity? Personally, I built my own file server so that I would have a backup of my data separate from my working PC.

Another good reason to have a networked server is easier access to data from multiple machines. For example, if you have an MP3 collection and want to listen to it from a home theater PC (HTPC) in the living room, it is easier to have all of your music centralized and browse straight to it over the network.

A Cooler MAaster 4-in-3 module in the external bays of the case. This allows me to use four more hard drives than the case normally supports.

Of course, you can store any collection of files on a server without having to maintain multiple copies of your data on several systems. If the file server is configured to use RAID 5 or RAID 6, it will also be able to withstand a hard drive failure (or two) without data loss, unlike information stored on a desktop PC with a single hard disk.

The Why's Of NAS

There are many different types of file servers. The simplest is a basic external hard drive, which is cheap, fast, and flexible. As long as your data fits on a single disk, that’s perhaps the most economical route to backup your files.

External hard drive enclosures can offer many different interfaces. USB 2.0 is perhaps the most common. It isn't very fast (480 Mb/s), but virtually every computer has USB connectivity. Another popular interface is FireWire. There are two different FireWire speeds: 400 and 800 Mb/s. Most enclosures that support FireWire come equipped with the 400 Mb/s type. In practice, it is even faster than USB. But unfortunately, it’s less ubiquitous than USB. The newest (and fastest) external storage interface is eSATA. Running at 3 Gb/s, it matches the performance of internal SATA ports and is able to serve up more bandwidth than any single mechanical drive is able to saturate.

My old file server. It has a generic case with good airflow.

All of these interfaces, which attach directly to a single computer, are examples of direct-attached storage (DAS). DAS’ strengths are its simplicity, performance, and cost. On the other hand, when the host computer is off, you can’t access any of the files housed on a direct-attached drive. Another limitation stems from connecting directly to a host machine. Generally, only that host will have access to the stored data, and if you try to share the drive over a network, performance on that machine suffers as client systems hammer the DAS device.

The way around the shortcomings of DAS is by not attaching your external storage to a computer at all, but to a network instead via network-attached storage (NAS). As long as a NAS appliance is powered on, it can be accessed from any computer on the network. Chances are good that you’ll attach the device through a single Gigabit Ethernet connection, which should be fast enough for most folks. If it isn’t, you probably won’t be rolling your own file server, but buying a high-end unit with multiple gigabit links, lots of storage space, and support for teaming. 

File servers of the DAS and NAS variety often accommodate multiple hard drives. Some enclosures hold two disks and some hold more. The box might support RAID 0 (striping, which can be faster than a single disk), RAID 1 (mirroring, which can protect you against a single disk failure), or RAID 5 (striping with parity, which can also protect you against a single disk failure). Some high-end boxes even support RAID 6, which is similar to RAID 5, but can tolerate two disks failing.

However, these RAID boxes have some limitations. They tend to be expensive. The Qnap TS-509 Pro costs $800 without storage, for example, but does support RAID 5 and 6. With that system, as with most ready-built storage boxes, you’re also forced to use the operating environment that is pre-installed, which might not be as flexible as the software you would prefer. Finally, while some retail NAS boxes can be expanded, most are limited to a single eSATA port or a couple of USB connectors.

So, let's see what we can do using conventional PC hardware to achieve the same NAS goal.

  • wuzy
    Yet again why is this article written so unprofessionally? (by an author I've never heard of) Any given facts or numbers are just so vague! It's vague because the author has no real technical knowledge behind this article and are basing mainly on experience instead. That is not good journalism for tech sites.

    When I meant by experience, I didn't mean by self-learning. I meant developing your own ideas and not doing extensive research on every technical aspects for the specific purpose.
  • wuzy
    And even if this is just a "Reader's Voice" I'd expect a minimum standard to be set by BoM on articles they publish to their website.
    Most IT professionals I have come to recognise in the Storage forum (including myself) can write a far higher caliber article than this.
  • motionridr8
    FreeNAS? Runs FreeBSD. Supports RAID. Includes tons of other features that yes, you can get working in a Linux build, but these all work with just the click of a box in the sleek web interface. Features include iTunes DAAP server, SMB Shares, AFP shares, FTP, SSH, UPnP Server, Rsync, Power Daemon just to name some. Installs on a 64MB usb stick. Mine has been running 24/7 for over a year with not a single problem. Designed to work with legacy or new hardware. I cant reccommend anything else.
  • bravesirrobin
    I've been thinking on and off about building my own NAS for around a year now. While this article is a decent overview of how Jeff builds his NAS's, I also find it dancing with vagueness as I'm trying to narrow my parts search. Are you really suggesting we use PCI-X server motherboards? Why? (Besides the fact that their bandwidth is separate from normal PCI lanes.) PCI Express has that same upside, and is much more available in a common motherboard.

    You explain the basic difference between fakeRAID and "read RAID" adequately, but why should I purchase a controller card at all? Motherboards have about six SATA ports, which is enough for your rig on page five. Since your builds are dual-CPU server machines to handle parity and RAID building, am I to assume you're not using a "real RAID" card that does the XOR calculations sans CPU? (HBA = Host Bus Adapter?)

    Also, why must your RAID cards support JBOD? You seem to prefer a RAID 5/6 setup. You lost me COMPLETELY there, unless you want to JBOD your OS disk and have the rest in a RAID? In that case, can't you just plug your OS disk into a motherboard SATA port and the rest of the drives into the controller?

    And about the CPU: do I really need two of them? You advise "a slow, cheap Phenom II", yet the entire story praises a board hosting two CPUs. Do I need one or two of these Phenoms -- isn't a nice quad core better than two separate dual core chips in terms of price and heat? What if I used a real RAID card to offload the calculations? Then I could use just one dual core chip, right? Or even a nice Conroe-L or Athlon single core?

    Finally, no mention of the FreeNAS operating system? I've heard about installing that on a CF reader so I wouldn't need an extra hard drive to store the OS. Is that better/worse than using "any recent Linux" distro? I'm no Linux genius so I was hoping an OS that's tailored to hosting a NAS would help me out instead of learning how to bend a full blown Linux OS to serve my NAS needs. This article didn't really answer any of my first-build NAS questions. :(

    Thanks for the tip about ECC memory, though. I'll do some price comparisons with those modules.
  • jimbofluffy
    "BSD Linux", whats that? I know of BSD.
  • ionoxx
    I find tat there is really no need for dual core processors in a file server. As long as you have a raid card capable of making it's own XOR calculations for the parity, all you need is the most energy efficient processor available. My file server at home is running a single core Intel Celeron 420 and I have 5 WD7500AAKS drives plugged to a HighPoint RocketRAID 2320. I copy over my gigabit network at speeds of up to 65MB/s. Idle, my power consumption is 105W and I can't imagine load being much higher. Though i have to say, my celeron barely makes the cut. The CPU usage goes up to 70% while there are network transfers, and my switch doesn't support jumbo frames.
  • raptor550
    Ummm... I appreciate the article but it might be more useful if it were written by someone with more practical and technical knowledge, no offense. I agree with wuzy and brave.

    Seriously, what is this talk about PCI-X and ECC? PCI-X is rare and outdated and ECC is useless and expensive. And dual CPU is not an option, remember electricity gets expensive when your talking 24x7. Get a cheap low power CPU with a full featured board and 6 HDDs and your good to go for much cheaper.

    Also your servers are embarrassing.
  • icepick314
    Have anyone tried NAS software such as FreeNAS?

    And I'm worried about RAID 5/6 becoming obsolete because the size of hard drive is becoming so large that error correction is almost impossible to recover when one of the hard drive dies, especially 1 TB sized ones...

    I've heard RAID 10 is a must in times of 1-2 TB hard drives are becoming more frequent...

    also can you write pro vs con on the slower 1.5-2 TB eco-friendly hard drives that are becoming popular due to low power consumption and heat generation?

    Thanks for the great beginner's guide to building your own file server...
  • icepick314
    Also what is the pro vs con in using motherboard's own RAID controller and using dedicated RAID controller card in single or multi-core processors or even multiple CPU?

    Most decent motherboards have RAID support built in but I think most are just RAID 5, 6 or JBOD....
  • Lans
    I like the fact the topic is being brought up and discussed but I seriously think the article needs to be expanded and cover a lot more details/alternative setup.

    For a long time I had a hardware raid-5 with 4 disk (PCI-X) on dual Athlon MP 1.2 ghz with 2 GB of ECC RAM (Tyan board, forgot exactly model). With hardware raid-5, I don't think you need such powerful CPUs. If I recalled, the raid controller cost about as much as 4x pretty cheap drives (smaller drives since I was doing raid and didn't need THAT much space, it at most 50% for the life of the server, also wanted to limit cost a bit).

    Then I decided all I really needed was a Pentium 3 with just 1 large disk (less reliable but good enough for what I needed).

    For past year or so, I have not had a fileserver up but planning to rebuild a very low powered one. I was eyeing the Sheeva Plug kind of thing. Or may be even a wireless router with usb storage support (Asus has a few models like that).

    Just to show how wide this topic is... :-)