Infinite Expandable NAS?

[Bugbait]

It's very hard to achieve "cheaply". A decent NAS will allow you to stack them, ie. Connect several together to form a single virtual storage volume. Even this has its limitations though. I know Thecus only support 5 devices in a stack last time I checked. This limits you to 5x8x3Tb (120tb - Although they may support >3Tb now for some models) of storage though.

You could do the same by chaining several PC's like others have suggested but this would require a bit of work.

[Fraz]

Cheap, infinitely expandable, low power requirements...

Sounds like you are chasing unicorns to me

[b0redom]

Another thought. If you only want to have a massive blob of storage, you could stack up servers and present iSCSI instead of one big blob. Each iSCSI LUN would be the max capacity of your individual server and you could mount it like this:

c:\iscsi\lun1
c:\iscsi\lun2
c:\iscsi\lun3

The iSCSI client for Windows is even free of charge, and if you use something like FreeNAS on the hardware, the server portion is free too. I use this to mount a chunk of space for Steam in the Windows bootcamp of my iMac. I presume you wouldn't want 100s of TBs of space at the root of a drive letter.

Something else to consider is noise and power draw. Before I downsized I had a server with a AOC-SASLP-MV8 (which I keep meaning to drop on the for sale section) and then later a Dell Perc 6i. I had a massive case with 3 of the 4 in 3 drive bay things. It sucked an immense amount of power and whilst it would be fine in a datacentre, sounded like a jet engine in the relative quiet of my under the stairs cupboard. It also sat at about 20% capacity.

Work out what you actually need, add 25% and buy that. In 12,24,36 months when you need more capacity everything will be cheaper floods notwithstanding!

[DanceswithUnix]

... Also I should be able to remove a hard drive from the NAS and plug the hard drive into another computer and all the data should still be accessible on that hard drive.

I haven't heard of anything that will let you do this bit, and for good reason.

Basically if you have one drive, then it should hopefully last a long time. There is a chance it won't but for most people the statistics work out fine.
If you buy 10 drives to put in a NAS, then the chance of a drive failing goes up 10x. Simple maths, but it starts changing the mind set from "if it fails" to "when one fails".

You can get some of that back by not buying standard drives. For example, a Western Digital RE4 drive has an MTBF of about 10x better than their standard desktop drives. Nothing wrong with the desktop models, just that the RE4 drives have extra bearings & stuff to make it longer lived, and hence you pay more than most people are prepared to pay for a desktop drive.

Even then you will get failures. To get around this any decent NAS will have some form of RAID, and that usually means spreading the data around along with extra copies of the data or something you can calculate the data from to get the lost data back. The simplest is the one you mention, just keep a second copy of the entire disk, called "RAID 1". The one for you is probably "RAID 5" where one disk gets used to store enough data that any other drive in the system can be recovered if it dies.

Just how much data are you hoping to store?

I suspect a big PC case with an energy efficient CPU/motherboard (Llano for example, not Atom) and running something like FreeNAS is the way forward for you.

Do you have an old PC kicking around that you can try FreeNAS on?

[GeorgeStorm]

You need to give more details as to exactly how much data etc you want to be storing, if it is A LOT, then I'm with the others about making your own
Getting some case which can take a fair few drives, then a cheap board and cpu (llano is a good idea) and then just shoving some like freenas on it (or even a full blown linux distro if you want to do more with it)