[HN Gopher] A disk is a bunch of bits
___________________________________________________________________
A disk is a bunch of bits
Author : dmazin
Score : 28 points
Date : 2023-07-19 14:41 UTC (8 hours ago)
(HTM) web link (www.cyberdemon.org)
(TXT) w3m dump (www.cyberdemon.org)
| gumby wrote:
| These days SSD "disks" _are_ just an array of bits. In the Old
| Days the disk driver had to know the physical geometry of the
| drive to optimise read /write head movement etc. Then the drive
| manufacturers made an array-like abstraction and did that work
| for you. Even today the SSD may remap your request for wear
| leveling and to avoid bad blocks, but they are so fast you can
| ignore that.
|
| (I wonder if the time delay due to remapping could be used as a
| covert channel? Probably not).
| tetha wrote:
| > (I wonder if the time delay due to remapping could be used as
| a covert channel? Probably not).
|
| Ach darn. They invoked it. I guess now we need a name, a logo
| and a migration plan back to spinning rust over the next two
| weeks for security reasons.
| omnicognate wrote:
| Nice article. I grew up when it wasn't really possible to be into
| computers and _not_ have a visceral sense of this. Presumably
| nowadays it would be possible to get very far into programming
| (maybe into a career in it!) without practically encountering
| storage-as-bunch-of-bits, although surely people know that 's
| what's there.
| toast0 wrote:
| It certainly is; my interview problem deals with bytes and
| optionally bits and I can't assume candidates have any
| knowledge of things at that level, because a lot of candidates
| don't. Kind of weird, IMHO, but not really a big deal, they can
| treat bytes as abstract constructs for the most part and go
| through the question well enough to show me if they can
| understand a problem described in words, figure out an output
| format and calculate example output given example input, and
| then write a program that does what they said it would do. The
| details of how bytes work can be explained on the way as
| needed.
| JohnFen wrote:
| > it would be possible to get very far into programming (maybe
| into a career in it!) without practically encountering storage-
| as-bunch-of-bits
|
| I increasingly meet devs who have no such knowledge (beyond a
| vague understanding). They sometimes don't even understand
| bitwise operations or when to use them and why.
|
| It completely boggles my mind.
| gumby wrote:
| I really hoped for the democratization of programming and now
| it's happened I sometimes have a WTF like that.
|
| But there's still a lot of call for programmers who
| understand the hardware and/or low-level protocols. We write
| the stuff the other people use to get their work done.
| JohnFen wrote:
| Oh, I agree.
|
| I don't think such devs are lesser in some way. They're
| just working at a high enough level of abstraction that
| such things aren't that relevant to what they're doing. The
| old fart in me does struggle to understand how people can
| learn to be devs without learning bit-level stuff, but
| that's just me noticing the strange new ways of a strange
| new world.
|
| And for devs like myself, who are happiest when working
| close to the metal, it's a professional advantage. As the
| pool of devs who know how to (and enjoy) twiddle bits
| shrinks, those of us who are left have more work and can
| command higher pay rates.
|
| The software industry is maturing and, like other
| industries that have matured, the people in it are
| increasingly specialists. My bit-twiddling ways are just a
| different specialty.
| AlexAndScripts wrote:
| I'm one of those new programmers. I'll sometimes do low
| level dev, but I don't use bitwise operations much. I
| guess I just don't recognise where they're useful. I'm
| always a bit awed when people chain a few for massive
| speedups.
|
| How can I learn?
___________________________________________________________________
(page generated 2023-07-19 23:01 UTC)