Network Attached Storage on a Budget?

Full'o'MP3 asks: "Wondering what to do with all those (formerly huge) hard disks on the shelves? Well, so am I. After looking at all sorts of USB enclosures, I remembered that, a long while ago, I saw a description/review/whatever of a small board (around 3" by 4") that essentially had an Ethernet interface on one end, a microcontroller in the middle and an IDE bus on the other end. It was designed only for that purpose, could not even format the hard disks on its own and only supported SMB without any access control, but by golly, I'm looking for about a dozen (or about 1 per 4 disks). Slap them inside old PC cases, fill them with hard disks, and you have a very simple, cheap file server for home or school. I've looked at a lot of embedded Linux and commercial storage stuff, but they are all overkill and require brand new hardware. Anyone have any pointers for this? (Butchering old laptops, iPAQs or similar stuff won't cut it...)" Readers may remember this thread from early May about doing something similar with new hardware. Since this is the "budget version" of the similar question, I felt it was deserving of its own post. How hard would such a device be to build fom old computer parts and hard disks? Details on cheap electronics (like the submittor-mentioned device) that would make this easier would be appreciated.

Comments

Just use old PC MBs

[ghostlibrary]

The cheapest/easiest method would be: snag some old 486 or Pentium systems, install 4 IDE devices per, add an ISA ethernet card, and put linux on it with the few services needed (networking, yp). Probably cost you, oh, free, since a lot of folks just are tossing old 486s/Pentiums. Or buy a bunch at your local gov't auction (NASA centers have these frequently, etc).

Re:Just use old PC MBs

[dasunt]

Actually, I did something similar. I have a Pentium 166mhz (AOpen), a 2 gig HDD, and a new 80 gig HDD. With only 16 megs of memory, and a stripped down version of debian on it, its fast enough to saturate the 10 mbit/sec connection via samba. On a 100 mbit/sec connection, I use about 30% of it. (IDE controller seems to be the limiting factor here - but I haven't found an ATA/100 controller that I can 'borrow' yet).

So, with new HDDs, your limiting factor should be the older IDE controllers in the motherboards. With old HDDs, the bottleneck should be the drive itself, which means that any old pentium-era machine will work.

As the other poster said, it should cost you free/close to free. Plus, since its all in software, its easy enough to turn it into an ftp server/smb server/webserver with just a few config files. Remember, linux only needs to see the boot partition, even with lilo, its possible to support large disks with bioses that don't recognize them.

Just my $.02

Re:Just use old PC MBs

[adolf]

I really doubt that the IDE interface is a limiting factor in such a machine.

I haven't met a low-end Pentium yet which is capable of saturating 100MHz ethernet, even in applications where disk IO is not part of the equation.

A new 80 gig drive would be vastly faster than the network, even at PIO 4 (16MB/sec, IIRC) or DMA33 or whatever old-school speed you've got the IDE interface running at.

If your network is not running full-duplex, you'll also have an impossible time saturating the wire because of that -- ethernet gets a lot more efficient when it can talk and listen at the same time, without looking out for collisions.

That all said, run bonnie or some other benchmark on the disk. If you see throughput in excess of, say, 7 or 8 megabytes per second, with sufficiently low CPU utilization to leave a bit for the overhead of tending to the NIC and Samba, then neither the hard disk nor its interface are any sort of bottleneck, and you should look elsewhere for an improvement in speed.

A P233MMX CPU can be had for less than $20, these days, and would probably be trivial to configure on your AOpen board.

FWIW, I've got a K6-2 350 router/file server/print machine, with a 30-gig drive of a couple years old. I haven't done fancy IDE interface tweaking under FreeBSD and have no idea what transfer mode it's using, and the motherboard is positively ancient so I'd be surprised if even DMA33 were an option. But it shoots files across the (half-duplex) network at 5 megabytes per second, generally, which I recall being a vast improvement over the Pentium machines which predated it.

Good luck!

Re:Just use old PC MBs

[mbyte]

my P233MMX with an promise UDMA 66 gives:

# hdparm -tT /dev/hdh /dev/hdh:
Timing buffer-cache reads: 128 MB in 3.10 seconds = 41.29 MB/sec
Timing buffered disk reads: 64 MB in 3.21 seconds = 19.94 MB/sec

So the harddrive can read twice as fast as max. network. Another question would be how much CPU is needed to get it on the wire ?

Btw .. is there any variant of NFS that uses hard drive caching ? i.e. make a special room of a few gig on the local harddrive to store frequently accessed data ? (this would speed up nfs-mounted /home quite a bit ! ;)

Cheap NAS

[Nyarly]

You can build your NAS on an old Linux box, without a doubt. My understanding is that using plain vanilla NFS with ext3 or similar is not going to get you the performance that a NAS appliance would.

Basically, the appliances use special filesystems and NVRAM along with retuned NFS in order to squeeze out the speed - to the point where some NAS is faster than local storage.

How much of this is available OSS, I wonder? Are there any NAS-ready filesystems out there? quickNFS? What about NVRAM cards/mbs and NFS to work with them?

Re:Cheap NAS

[n9hmg]

Not all NAS vendors are doing that kind of optimization. Some vendors are making very-low-end systems, just like he's describing - actually, in my main experience, much lower-end. We standardized on the Maxtor MaxAttach NAS 4000 320GB machines, which are p166/64MB/4x80GBIDE, running FreeBSD 2.5. While we were negotiating the deal, they decided to end-of-life this new product, and have left it as an unreliable, poorly-performing product. They even refuse to fix the problem where the box locks up on reboot if rebooted while filesystems are mounted from the NFS shares.
The basic concept is solid, and i'm probably going to end up doing just what the article is about, though with slightly-higher-end hardware, so I can buy a hundred or so identical systems, make an image, and splat it onto them all. It should come in at about 25% what all the NAS vendors are asking for equivalent products.

the older the hardware, the less reliable

[oliverthered]

Not so true,
New hardware has a higher fail rate than hardware 2 years old, because all the hardware that dies in the first 6 months is already dead after 2 years.

Also, mass production of old hardware might not have come upto speed, components of far higher quality than required may have been used.

e.g. The first CD players have far better lasers

current CD players use top emitting laser diodes,
old CD players use better side emitting laser diodes.

The spindle on old CD players was manufactured to a stupid precision ( a few atoms or something)
because they could make crap spindles or amazing spindles but not ones just good enough.

I should imagine the same is true with a lot of electrical equipment

I have a 30year old
Fridge,TV,hair dryer,dish washer etc.... and they all work fine.....

Re:the older the hardware, the less reliable

[afidel]

actuall the first generation of cd players have laser with much shorter run lifes and much, much crappier AGC circuitry which makes them less capable of recovering from disk inperfections and scratches. Besides modern cd players have multifrequency lasers for multiread compatibility.

Throw the Drives Away -- Electricity Ain't Free

[InitZero]

I got a hold of a bunch of Sun SCSI four-drive disk enclosures. I had an equally large bunch of four to 18 gig drives. Add in a few surplus SCSI cards and I ended up with more than 100 gig worth of disk space attached to a small linux box.

The drives were quick enough (more spindles = more speed) for a small media server and I had no complaints.

That was, until I noticed that my home office was now running six to eight degress warmer than the rest of the house. That got me to thinking about how much juice these guys draw. All told, I would be paying an extra few bucks a month in power.

The straw that finally broke the camel's back was that having a dozen additional filesystems (yes, I could have striped them) to manage was a pain in the buttocks.

In the end, I gave the drives to someone who had more time on his hands and bought myself a pair of 100-gig IDE drives.

I don't know what you consider 'formerly huge' but unless your drives are bigger than 40 or 60-gig, it may not be worth your time. I know it would not be worth my time nor my electricity.

InitZero

Performance Tuning can make a big difference

[bill_mcgonigle]

Check out the FAQ.

I found that ext3 in data=journal mode got sync performance back up near async performance (which you almost never want). The NVRAM disk might be a good route; they're pricey but still cheaper than commercial NAS.

Does anyone have any good experience with particular NVRAM units?

Um... why?

[Wakko Warner]

Buy a 3Ware Escalade RAID card. The real money is going to go to hard drives anyway; you're not going to save much by buying cheap-ass featureless controllers. At least, with real hardware RAID you're getting some resiliency.

- A.P.