Orchid XP v8 wrote:
> 
> Is that software RAID or hardware RAID?

Software. Real HW-RAID costs incredible amounts of money and software is 
easily trustable enough for home usage.

> My dad went with a hardware RAID solution, and it was utterly useless. 
> You had to resilver it every few hours because it kept breaking.

It was some random bulk-card and I'd doubt how hardware based it 
actually was, but since RAID-1 is only a mirroring, it's possible to do 
cheaply.

> 
> Ever tried to perform a low-level format on a HD? 

Yes. It was the time when 120MB disk died and it was worthy enough to 
try to rewake (yes, I succeeded).

> No matter what size it 
> is, it always takes an extremely long time. (The bigger the drive, the 
> faster it is, but the power to weight ratio seems fairly constant, so it 
> always takes a long time.) 

OTOH today you can format multiple drives at once without significant 
loss in time.

> Formatting a huge drive with, say, FAT or 
> NTFS only takes a few minutes, but a low-level format takes an hour or 
> more.

Yes. Formatting to ext3 or XFS takes a moment more, since the system 
also creates journaling ;).

> Resilvering the mirror was similar. It's mirrored at the hardware level, 
> so the disks must be block-by-block identical.

Linux keeps the software-RAID-1 block-by-block -identical also - and it 
drops the disk from the array if it can't do that. What it doesn't do is 
dropping the disk from the array if it works, so if you'll get a drop, 
you know you're going to have a need to replace that drive - either 
immediality or really soon.

> 
> Yeah, I guess... Doesn't seem like you're gaining a huge amount, but I 
> guess it's better than nothing.

Do backups ever seem like gaining a huge amount? Think again. How does 
external HD differ from LTO-tape in
1) in virus-case, when all online files are compromised or deleted
2) when your running data-disk breaks up
3) when you'll accidentally press "delete"
4) when the flood comes through your roof
5) when some looney robs your laptop

And yes, if your house burns down or your roofs gives up and lets the 
water in, you do have a bigger problem than your binary data. But it 
doesn't remove the dataloss being a problem, it just cumulates all other 
problems on top of it.

> 
> ...in other words, a HD. Like what I said. :-P
> 

Yep.

-- 
Eero "Aero" Ahonen
    http://www.zbxt.net
       aer### [at] removethiszbxtnetinvalid

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