Topic: Geeky question

[DJ Doena]

Stupid question but... What is the capacity of that in Go to help me understand?

1 Terabyte = 1,000 Gigabyte = 1,000,000 Megabyte (When it comes to HDD manufacturers, for me as an IT guy 1 Terabyte is still 1,024 Gigabyte (2^10) = 1,048,576 Megabyte (2^20).

I assume that "Go" stands for "Gigaoctet" like in France? If so, Byte = Octet.

[RossRoy]

1TB external hard drive

What is the capacity of that in Go to help me understand?

1TB = 1024GB

But once formatted, there's 902GB available. Which may cause problems.. My NAS data pool has 1.0TB reported as available. I'm gonna have to buy a second hard drive if I ever fill this data pool! hehe But there's still a while to go (only 494GB used as of this morning)

The first hard drive I've ever had was a 10MB.. top of the line at the time! With a whopping 4MB of RAM, which we upgraded to 8MB (400$!) and were chips you had to solder on the motherboard!

PC's sure have evolved..

[DJ Doena]

But once formatted, there's 902GB available.

That's because HDD manufacturers have decided to use the SI system (base 10). Thta means that for them 1 Kilobyte are 1000 Bytes just like 1 Kilogramm are 1000 Gram and 1 Kilometer are 1000 Meters.

Computers use the Binary system (base 2) which leads to these differences. Computer people traditionally mean 2^10 (1024) Bytes when they talk about a Kilobyte and not 1000 Bytes. Windows also uses the binary system.

So when a HDD manufacturer sells you a HDD with "1 TB" he means 10^12 (1,000,000,000,000) Bytes and not 2^40 (1,099,511,627,776) Bytes.

But Windows will tell you that 10^12 (1,000,000,000,000) Bytes are only 0.9095 Terabytes.

See also: http://en.wikipedia.org/wiki/Binary_prefixes#Computer_memory (from there on downwards)

[RossRoy]

But once formatted, there's 902GB available.

That's because HDD manufacturers have decided to use the SI system (base 10).

I knew that   And I hate that practice.. I can't even begin to count the number of times people have called me saying "the invoice says it's a 320GB drive but windows says it's only ~298GB, what gives?" I was just mentioning it in regards to the lack of around 100GB to actually fully backup the NAS.

But then, the drive is already defective! It happily accepted all my backup data during the night.. but now, if I try to access it, all I hear is a clicking sound (like when the head moves to the parking position after turning off the drive) and nothing happens. The system even grinds to a halt. I tried turning off the hard drive, rebooting the machine, nothing. The drive is dead. And after what I've read these last few days (about 50% split between reliable and dead after 1 to 4 months) I'm getting a refund and going for a more "reputable" maker (the drive was a Fantom Drive enclosure, with a Hitachi drive inside.. Guess I'll now go for a LaCie or a Western Digital... even if they are twice the price).

Anybody have experience with eSata docking stations that accept standard internal hard drives? Like this one?

Because I'm getting fed up with actual external hard drives... Each one I've had so far, either company built and custom built by buying an enclosure, has died within months.. So I'd rather get something I know is reliable (internal hard drives) and stick it in something that will not hinder air circulation (the docking station).

[RossRoy]

Well well.. Looks like the decision to go with a single parity RAID setup was the right one. My data pool is currently in the "degraded" state. One of the device "cannot be opened". Turns out of my hard drive just went offline for some reason.

So I'm off to do some diagnostics!

It's funny how things go though. Yesterday, I did a scrub of all the data on the NAS. Came up with 1 checksum error on device ad10. So this morning I ran HDD Regenerator on ad10 to see if there's a bad sector of something. Nothing found. SMART also didn't log any error. So I thought all's well.

And now, the disc is not even recognized by the system. <sigh>