I do wonder a lot about HDD reliability.

I work in a computer repair shop, and the number one problem we see is HDDs. Even if they are still readable, a lot of Windows errors are down to drives which are failing and have had to remap a lot of bad blocks.

Having said that, I own quite a lot of HDDs are most are fine. They just sit there all day, getting maybe 8 hours use and never has one failed on me.

500GB drives are very tempting, but it is a lot to loose. I suppose it depends how valuable the data is. I could re-rip stuff I guess. Having said that, say you have 500GB on DVDs in a box. If the box somehow gets damaged, or you store it incorrectly, or all the discs age at roughly the same rate and the dyes deteriorate...

Also, even at work drives don't often die completly. Usually, there are warning signs and plenty of time to rescue data. The warning signs usually come from Windows errors though, however there are ways of telling. SMART is actually quite good at predictiing errors, the problem is most SMART monitoring software is not paranoid enough. We use PC-Check, which runs stand-alone from Windows. If there are more than three entries of any kind in the SMART log, it fails the drive. Most SMART monitoring software waits until manufacturer defined thresholds are exceeded, which can often be too late. This is presumably because manufacturers don't want so many returns.

USB/firewire enclosures generally do not support SMART. By the time they start clunking, it's too late.

I use PAR2 parity for DVDs. An automated solution for HDDs would be nice.

A computer repair shop is going to give you a severely biased sample. From my experience, the number one reason for dead hard drives is overheating. Most computers have highly restricted or practically nonexistent front intakes.

Before I made any conscious attempt to keep my hard drives cool, I lost two or three of them a year. After I made the BRILLIANT realization that I was cooking my hard drives to death, I haven't lost a single one.

Mojo, here's a good guess why you haven't had a hard drive fail at home... you probably bought quality motherboards =)

hooking up a hdd drive to a junky motherboard is like handing your newborn baby over the a group of monkeys to baby sit while you head off to wallmart....eventually it will all end up in disaster.

Interesting theories guys.

Of course, a computer repair shop is not a good place to base assumptions on, because naturally every PC that comes in is broken

I think you are both right. Excessive heat and poor quality components don't hurt. I'd say a cheap PSU is a really killer for HDDs. Power isses can cause seek failures or read/write failures, which enter the SMART log and cause the HDD to remap blocks that might be okay.

...

So, it looks like the main thing we need to find now is a suitable case for a uATX mobo and a few HDDs. Preferably cheap. We need a good PSU to pair with it. Need not be high power.

Ive been building my own cases for awhile now out of PVC foam boards, they are pretty easy to put together, and durable enough. don't let the term "foam" fool you they are pretty solid and if I smack my wife's rear end with them she gets angry, and a little randy

best thing about building a case out of PVC foam sheets is that it cost maybe $18 to do (includes shipping) buy a small tube of cyanoacrlate (sp?) glue and a little sand paper and a cheapo box cutter and you can make a case precisely the size you need to hold precisely the components you want.

Wake-on-LAN is Standby Mode. It just means that instead of having to press a button on the computer to wake it up, you run a program on a different computer that wakes up the sleeping computer over the network. This way, the NAS can be in an out of the way place without the inconvenience. Wake-on-LAN must be supported in BIOS (just like any other sleep modes), but it is not uncommon.

This is an interesting idea. I have a spare drive cage from an old computer. Fitted out in a foam case with a 120mm fan, it would be ideal. Stick a grill on the front, fan and PSU at the back. Maybe use a DC-DC PSU, or just a very small one...

This was a major concern for me when I wanted to do some data storage.

Ultimately, for low power storage, you want a commercial NAS. There is no question about this. The reason being is that commercial NASes can utilize parts that are much lower powered than most anything you can build on your own. Unlike their hobbyist counter parts, NAS hardware is built primarily with one general task in mind. You won't find sound cards, video cards or anything else that can draw power even when left unused. In fact, in some cases, you can get a non-x86 processor to do most of your computing for you (which is MUCH tougher to get for most folks).

Ultimately, I suspect one of the best low powered NASes you could get would be the Thecus 4100, since it can power down the drives and uses an Intel XScale processor. Unfortunately, it's bloody expensive and unusually loud.

(FWIW, I own the 5200 Thecus NAS, and though terribly convenient, it's still bloody loud. And I'm reluctant to mod this sucker given how much it cost me).

Commercial NAS devices like those from Thecus are very power efficient, I believe they are in the 35Watt range, the big problem is they are very expensive and are limited in what kind of services they can run.

I started a different thread that touches on the subjest "the 65watt challenge"
http://www.silentpcreview.com/forums/vi ... highlight=

it's possible to build a low power system *with the disks* for about the same price as and empty commercial NAS product. That means saving $300 or more assuming you don't mind setting up the software yourself.

The X-raid's ability to dynamically expand a raid 5 array is fantastic, although I seem to remember that "open filer" has this ability too.....hopefully someone can shed some light on that.

Since we can't easily purchase commercial componenets like those used in the thecus, I am turning my attention towards the new DTX standard from AMD. The size of the DTX formfactor is right on the mark for home NAS boxes and hopefully we can lok forward to reduced levels of power consumption.

also important to note - not alll commercial NAS performance is the same - many are quite slow (eeek buffalo terra station) but you certianly can't beat the convenience or a box that's all setup and ready to go immediately.

It's a real shame NAS boards are so expensive. They need not be. You can get a single drive NAS enclosure for £25. The board must be tiny as it's about the same size as a USB enclosure... and it wouldn't be much more expensive to add a few more IDE/SATA ports.

Regarding motherboards, if you don't mind hacking them you could probably do quite a bit of power reduction on them. Simply lift/cut the power pins on chips you don't need - sound, extra USBs, even video maybe. Shame things like serial/parallel and PCI/AGP bus controllers are all integrated. It would depend on how willing the BIOS is to boot with things not working, but in my experience with broken mobos it's usually not a problem at all.

Mojo, I don't think those single disk NAS are even worth the £25. Even though they claim to support Fast Ethernet, actual testing shows transfer rates around 1-2 MBps. That is about 1/20 of what the drive is capable of and 1/10 of what you get over the USB interface. I don't know if it's a case of poor overall design or what, given how cheap good components are, but these things really suck as NAS. Basically, they are external USB enclosures with an RJ-45 jack for show!

Indeed, reviews say they are rubbish... oh well.

The quest is still on for a suitable case though.