10 hours 41 minutes
right, And this module will talk about hard drive technology, various types,
traditional hard drives, our data storage devices designed, a storage store, massive amounts of information we can't store lot and ram. We can't store a lot of static on the motherboard. These are all small, short term solutions for storing memories so hard. This is our
solution for being a rewrite. Data on a large scale
floppies were too small to be able to hold a lot CD ROM's or write once, for the most part, even the rewriteable ZX. It takes a while to write to them and be on to reuse them.
They're made up of magnetized loom platters, hard drive, standard hard drives, very mechanical with Rian, right heads that retrieve data and load onto Ram. They give it like a record player,
so, as the record turns with the platter turns the speed that turns as measured in rotations per minute. So the faster it turned the fasten it that head, which you can see in this picture.
I think of it again, like the needle record player can read data off the desk so you get better performance of a faster disc.
The most common one for desktops is 7200 rpm. 17 rotation for minutes.
laptops. Lot of times will come with hard drives are 5400 rpm
because even though they're slower by virtue of than being slower, they also use less power, which is good for portable devices. So we want slower, um, and that you're not using the desktop to do high video adding or any kind of high performance of the trade off. You'd rather have the power than
the performance the trade off
25,000 rpm. They're more likely to be seen in servers
or high end workstations that would be used for audio and video waiting, for instance.
Just like with almost everything in computers, he is always an issue. The faster the drive,
the bigger the he concerns. So you'll see high end drives will have heat sinks on them
if they're super fast to avoid them from overheating. You can also buy, um,
cooler fans specifically for hard drives that will fit around them in the bay if they're overheating.
You're gonna stall additional fans in the bays like I just mentioned.
Maybe the case is too small so the heat splitting up and has nowhere to go.
Traditional problems with hard drive It takes time to spin up again. It's mechanical. So, um,
when you first taught a computer gets power, you gotta wait for the hard drive to finish pinning up and getting up to that initial speed. Kind of like getting up to 55 miles an hour car. You could be right At 55 you have to work your way up to 55. Same thing with the hard drive. It's gonna reach up to its speed. Now. We're not talking the same time. A car would take its
quite a bit faster and reaching its
speed. But that's still a delay. So it can't read or write until it gets up to that operating speeds that something's gonna wait for us. That could be a delay in booting your system because you need you gotta wait till that comes up before you can do anything.
and some in some servers. It's been issues where if you have too many hard drives, all of them trying to spin it at once could be too great a pole because all that we're gonna pull all the power requirements from the power supply at the same time.
So well, in that case, a lot of times in the BIOS you can set delay spin ups
Okay, this hard drive spins up first. This one waits two seconds and then tries to spin up.
This one waits four seconds, this one wait six seconds. So it may take you maybe 30 seconds to get all your drives. If you're it's a
big file server, but it avoids that huge load
and draw on the par supply. At first, Boot said, I'd be That's going to be aware of and even see that option sometimes in regular desktop PCs where you can delay this spin up of a hard drive
and they're susceptible wear and tear. I know personally, you have very careful with him because you're talking
little needles, magnets on a head. Think of it like just like a record player, just like record. They can scratch your easily. And although you can't actually see those heads, you know the case falling over on sides enough sometimes just damage the head, and that means that head's gonna hit the plate, and that's gonna cause a scratch. And just like in a CD or record,
if you cause a scratch on the platter that could cause damage to be lost
and permanent damage also,
and since his mechanical, it's subject to wear and tear, especially over time. If being used a lot, you gotta be aware, though this drive's been being used for five years straight, I probably replace it just kind of wear and tear
with mechanical stuff.
The long came solid state drives. Think of solid state drive. It's kind of like,
USB flash drives, but faster. So instead of being mechanical,
it's all electronic. Its memory chips
that can save data after powers law. So
kind of the best of both worlds. They're bigger than Ram. Um,
but they also saved the data on like ran When you lose power, all the dad is gone
s all those issues were just talking about with heat and about where and tear and the platters and wreck the heads hitting the planet stuff. All those problems are gone with SST
because we don't have any mechanical parts anymore. Mixologist memory chips
specifically bubble memory. So the advantages of SST czar that they, uh, are faster read,
but slower, too, right?
So a common practice when using SS D's in a desktop environment is put your operating system on the SSD drive
because that drives fast. It reading and your operating system follows don't change often. So put your operating system on the SST and then put all your other data files, like
any videos and music and
other large files on a mechanical drive, because larger mechanical drives were cheaper than SST. Also,
the city's air still rather expensive.
So if you're doing a lot of stuff that's read, only put down the SST, and that's a pretty common practice and desktop computers right now, because you're really notice the difference that when you boot off SSD drive with your operating system
is incredibly fast.
Besides, the cost of it does, it produces less he, and it causes, uh,
pulls less power to. So it's very energy efficient because there's no movie mechanical parts
durability. It does have a shorter theoretical lifetime
than a mechanical drive because of how many times you can rewrite to the memory.
it's not that large concern unless you're using in a heavy right environment like maybe a database, which it wouldn't be optimal for anyways, because they're not good for right there. Better for Reed, the technology would probably outdated. Before you'd actually reached the limit of a SST is number of rewrites.
I kind of like CR W's directly have a limit to how many times you rewrite on. But
I've never used a CD R W that that many times to get to the
Another kind of discover another kind of this technology is raids redundant. Rave independent. This using multiple distance store data and she redundancy.
Well, there's two kinds of common types of raid. We have the hardware base where it's
done through at the BIOS level through either
actually sitting on the motherboard or sitting through an ad on card that provides raid capabilities
when it's at the hardware level. If I do a raid zero, which is to dis striped look like one drive, it's gonna look like one drive to the OS, and everything else will be handled by the hardware. So I'm not gonna Only the BIOS is gonna know. It's actually two drives. Us has no idea to raid. Now software based lets you have a few more options,
but that's done at the OS level.
And the problem with that is
you can lose
if the OS gets lost. For some reason, you also lose. Lose all your data about your raid, which could cause problem, especially if you're doing
a stripe. You might lose.
You might lose the information about the mirror or about the two drives being together, and you won't be able to pull it off because the information that contain
the correlation between the two drives were saved in the OS and not the bio, so that the BIOS is kind of safer at the harbor level. Software raids are cheaper and easier to implement, though didn't require an additional hardware.
Ah, but also, since they're not using additional hardware, they're taking more of a toll on the CPU of the system. Instead of having a totem dedicated hardware to do that
And if it's at a software level, it can also not provide redundancy to boot volume because it's part of the boot volume of the O. S.