Book Chapter 9 - Implementing Mass Storage

2. RAID

Okay, Pick a drive, any drive, whatever you want. Okay? The reason I have multiple drives in front of me, right, is that a long time ago, disc drives were expensive. I know today you go to a store and you find a disc drive for $300, and you think that's expensive. I'm talking about early first generation discdrives that cost millions of dollars. So after a while, as hard drives started to get smaller, a bunch of guys in Berkeley kind of got together, knowBerkeley, so they're groovy and they're like, you know, we could have some really cool synergy if we, instead of using one drive for anything, used multiple drives that acted as a group or an array to do groovy stuff. And what these guys came up with was a type of drive organisation known as Raid. You see, the idea behind Raidis to provide two nice things. Nice things. The first benefit is speed, and the second is data redundancy. So these guys in Berkeley came up with what we call Raid levels that define how you get drives to work together and do stuff. So these raids have things like Raid Zero and rate five.

And what I want to do in this episode is go through popular Raid levels so you can conceptualise what Raid can do for us. Look, so the first grade level I want to talk about is called Raid Zero or Stripe. Raid Zero, or Striping, requires an absolute minimum of two drives, although you can add more if you want. The idea behind striping is that, let's say I've got a huge Microsoft Word document that I want to save. So slicing works by taking a piece of the file and storing it on the first drive. Then we take their piece and store it on the second drive. And then we take another piece and put it back on the first drive, and then another piece and put it on the second drive. And we keep going like that until the file is saved. The beautiful thing about hyping is that we're having two drives accept the data. So with rate zero, you get speed. The downside to rate zero is that you don't have any data safety at all. If either one of these drivesdie, you're going to lose everything. Not just that Word document, but anything else you might have stored on those drives. So let's take a look at the next step up in Raid One. With Raid One, better known as Mirroring, we use two drives. Now, you can also use four, but we're going to keep it simple for the moment and say we can only do two drives for this. So Raid One, also known as Mirroring, works something like this.

Let's take that exact document, except this time we're going to take the first little piece, and we're going to put one copy here, and we're going to put another copy here. And then we take the next piece and we make another copy here, another copy here, and the next piece. And we just keep going until the entire document is saved. So with this, we get redundancy. As a result, raid one or mirroring provides security. However, in most cases, it actually slows us down because you're asking your hard drive controller to write the exact same piece of data twice. So what we want to do now is we like the redundancy, but we'd like to have a little speed at the same time. And while we're at it, I don't want to use too many drives if I can help it. So the Raid guys went through a number of other types of raids with names like Raid Two, Raid Three, and Raid Four. And in my entire life, I have never seen a commercial product that uses grade levels except once. And I had a lot more hair back then. So the next really popular Raid level that they came up with was called Raid Five. And that's striping with parity. Let's see how that works. Grade level five requires a minimum of three drives,although you could do more if you want to. And it works something like this, using that same document. What we're going to do is we're going to take this first piece and we're going to put it on the first drive. Then we're going to take this second piece, and then we're going to put it on the second drive. Except now we're going to do something really interesting. Interesting binary math. We can, in essence, multiply these together and create what we call a parity value that's the exact same size as these first two pieces.

By doing this, if any one of these drives dies, we can, on the fly and automagically reversingthe math, recreate this type of data. So we just keep going. We take another piece and we're going to put it over here. And then we take another piece and put it over here, the mathemumbo jumbo. Then we create another gap. Rate five, or striking withparity, has been popular for decades. The only downside to rating five is that you can only drive one time. If you lose more than one drive, you're not going to be able to rebuild the data. However, you get pretty good speed and data redundancy with this. So rate zero, one, and five were the big popular ones for a long time, but today we see a lot more. like, for example, rate six. Rate level six requires a minimum of four times. And the idea here is to go ahead and use the same document, except this time what we're going to do is we're going to copy one piece of the document, copy another piece of the document, and then we go through some absolutely fascinating mathemo jumbo and absolutely generate two parodys for those two pieces of data. Raid Six is more popular these days than Raid Five for one simple reason. When we're doing grade six, we can lose up to two drives before we lose any data. So it's a little bit more expensive in terms of the amount of real estate and how many drives you need, but you get more redundancy because you can lose up to two drives and still get where you want to go.

These are wonderful ways to do things, but there have been a few occasions when we have used multiple levels of all at the same time. And we refer to these as raid ten, rate one plus zero, or 10 or rate zero plus one. These combine striping and mirroring in different interesting ways. Let's go and start with raid ten with a rate. What we do is strip mirrors. So what do we have, and you have to have a minimum of four drives to do this? Technically, you have to have two pairs. So right here we've got one mirrored pair. So this is running raid one, and here we have another mirrored pair also running raid one. However, in this case, what happens is we take one piece of data coming off and we put a copy here and here. So we've mirrored it and then we take another piece and we strip it across to these two guys. And then we just keep going and we're makingmirrors. Stripe it across to the other mirrored pair. So these are mirrored, and we stripe the two mirrored pairs. The nice part about raid ten is that I can lose one of the mirrored pairs on each side and I'm still in good shape. The downside is that if I lose one mirrored pair, I'm not in trouble because we've lost half of the stripes. So an alternative way to do this is to spin it around and do rate zeroplus one, which means to mirror some stripes.

Rate zero plus one also requires a minimum of two pairs. Now in this case, what we're going to do is we're going to mirror the stripes. So this is a striped set. So we're going to take a piece of data and we're going to put it on the first one. Then we're going to take another piece of data and put it on the second one. And then we're going to take this data and bring it over here to mirror. So we have two stripes and then we mirror them and we just keep going through, grabbing another piece, grabbing another piece, mirroring thatidentically until we're all the way through. So with rate zero plus one, we can lose one complete striped pair on either side and we're okay. The downside would be that if we were on each side, we wouldn't be able to rebuild the mirror, and we'd be in trouble. So do we do raid one plus zero or raid zero plus one? You know what, it's your choice. I'm just here to cheat on different kinds of raids. Okay? But realistically, we have all these different ways to do raid. The problem that we run into is, well, how do you do it? I mean, it's nice that Mike here talks about all these things, but how do we actually make it happen? Well, you have two choices here. You can do choice number one through hardware. Now through hardware, we're talking about using dedicated controllers that are built into your motherboards or a card.

You can stamp in and we hook our drives up to that controller and go, okay, we want you to beRaid One or Raid Five or whatever it might be. So we go in and figure that this and that is often done through system set up or through an optional bias that gets set up. And then, once it's set up in what we call an array, you fire up the operating system, and the operating system just lives on a great big D drive or something like that. The other alternative is to do it through software, usually through your operating system itself. Most operating systems support some level of first aid built in. And in that case, what you're going to do is you're going to run some kind of software within the operating system to set up the array and configure it the way you want. So we're going to do both of those. There is one more type of rate I want to talk about. It doesn't really have a number per se associated with it, and that is that it's a more advanced type of raid. They are called proprietary. I call them proprietary raids. Companies like, for example, Synology, who sell these wonderful systems, I can install four hard drives in one small box and configure it as a Raid Zero, Raid One, Raid Five, Raid Six, or Synology's proprietary format. You don't know how it works; they're not going to tell you, but it has some real efficiencies to it. Even Microsoft Windows, with their popular storage option, allows people to set up a raid array that isn't any particular form of raid, but Microsoft's own built-in proprietary system.

3. Hardware RAID

If you really want to see Raid in action, the most fun way to do it, in my opinion, is to hard wade. Now, hardware Raid means that we have some kind of slick high-end controller that talks to the drives and helps configure them as Raid Zero, Raid One, Raid Five, Raid Ten, or whatever it might be, and it does all the configuration. And then when we boot into the operating system, this big array that we've set up just shows up as a single drive letter. You don't necessarily have a high-end controller these days if you've got a desktop system. Lots and lots. More than half of all desktop motherboards now have built-in Raid controllers soldered to the motherboard, and this one does as well. So what I've got here is my big box, and I've got 1234 identical four-terabyte hard drives all buckled in. Now you've got to be a little careful when you're setting up rate in these types of systems. Right now I'm booting off an M2 drive. It's got Windows installed and ready to go. So, first and foremost, we'll need to go into themother and look for a setting that says "don't treat these guys as regular harddrives, they're not AHCI, regular old hard drives." Instead, treat them as a raid array. We do this a whole new extra, not nearly as fancy as a system setup we've seen, but another system setup is going to show up, not for us to configure the system, but just figure out the raid array.

So what I want to do right now is go ahead and boot this system, go into some setup, and let's change this from AHCI to Raid. I've gone ahead and booted into my setup because I want you to see all the different drives I have in here. So right now what I've got is four terabyte SATA hard drives. Right, you can see this is actually interesting. He advertises this really big as AHCI mode, which basically means we can't do any of this groovy Raid stuff. Now also notice right there underneath my mouse, you'll see where it says Samsung SSD that already has Windows Ten installed on it. So what I'm going to do is go from AHCI mode to Raid mode, and every system setup has some option on this one. It's just kind of particularly pretty and easy to get to. And now I've set it to raid mode. Now that it's in raid mode, those four drives will effectively vanish; they'll be dedicated to being raid drives, and we'll see a completely different system setup appear as soon as I reboot this system. Now watch really carefully. Watch closely. You're going to see something you haven't seen before. Right there. Did you see it said "Control R"? Ladies and gentlemen, welcome to your first hardware rating. As you can see, because we switched from AHCI to Raid, we now see these four terabyte data drives ready to go. So what we're going to do is we're going to go ahead and cry. I've actually been in here for a moment and I went through that initialization already.

Now it's going to say which disc you want for this array. So just for fun, I'm going to solve four. And there in the lower right hand corner, it says "A for all and enter when you're done." So it says, "Okay, you've given me four drives." What kind of rate array do you want? And right now, I can see there are some options. I can perform at rate zero. I can do raid ten. And I'm very disappointed to see what happens when I select grade five. Looking for the left-hand corner I guess these guys want a little more money off of me or something. Or maybe there's a flashable rom I can get there. I can get these to all light up, but it still works fine. Let's go ahead and just do Raid Ten. So it's I've got all the information I want here, so okay, here we go. And it actually has a cache mode in this particular case. I'm going to ignore that. I just want to read this here and then C to confirm. And I have made an array. So that's actually fascinating. What I've done is I've made a Raid Tensimply by going into the system right here, getting that Control R, and it's up and ready to go. The last thing to do at this point is to just continue on to the boot. Let's boot into Windows and see itarray the way Windows sees it. Now, as we boot into disc management, you'll see, hey, it's the C drive. We still make it an MBR GPT. I'm a GPT kind of guy. So we'll go here and all of a sudden we have this big old two-terabyte drive. Because when it comes to where the operating system only sees the array when it's set up by the raid controller.

So I don't know if you noticed while we were setting up the raid array that there were some extra options, some special features. For example, we have something called a hotspare in there, or a swappable drive. What we're talking about is how with Raidyou can do some cool stuff. Remember, the beauty of Raid is that if one drive is full, then another drive can be plugged in to place it. With certain hardware raids, you can have that drive sitting there ready to go. It sits there for months and does nothing until that one magic day when one of your drives dies and it automatically jumps in. It doesn't physically move, but it automatically jumps in and rebuilds your array. Automatically and then later, just pull out the bad hard drive, shove another one in, and you've got another, what we call a hot spare to go. Now, we've got to be careful with the term "hot swappable." Hot swappable simply means that I don't have to shut my system down to yank out the hard drive and plug it back in. Unfortunately, in the system, it really can't be done. We can't make a spare, but in order to make it swappable, we'd have to use the more advanced controller than the free one that comes with my system. We could already tell they were skimping on the luxuries. I really want to do hardware raid correctly. I'm probably going to have to go out and spend three to $400 on a really advanced controller. It gives me a little extra control and I don't have to worry about licencing fees.

4. Mass Storage Troubleshooting

One of the things that always cracks me up about the CompTIA exams is that invariably they'll have some objectives saying, "Here are all the problems that you could ever run into with mass storage." What do you do about these types of symptoms? Oh, I'm the great Mike Stromany. I'm going to take on CompTIA head to head and I'm going to answer the questions. Before we do that, let me give you two rules when it comes to problems with mass storage. Number one, back it up. Step up, even if that means just throwing in the thumb drive and copying those precious photos or those documents or whatever it is. Make a backup of whatever you're working on because you might only have one shot at this and then it's going to be too late or very, very expensive. So make a backup. Number two, mental reinstall. Any time you're having a problem with a device, in particular, if it's a new device that you've just plugged in and it's not doing what you want it to do, go through the mental process of reinstalling it just from the ground up. And you'll probably remember that one step that you'd forgotten. Also, when you're doing that mental reinstall, do what I call the triple check. Oh, I've already checked that. Well, check it. Well, I've already checked it. Check it again, because most problems with mass storage are caused not by them breaking, but by us as technicians forgetting a simple step. OK, you've got a backup; you've done a mental reinstall. Let's hit those problems. You ready? Bring them to CompTIA. Yeah, Okay, So either the rate is not found or the raid ceases to function. These are the ones that come into play with raid arrays. Number one, a raid that is not found, assumes that it's never been installed before. The big issue to look out for is: is your rate controller active? Do you have the right drivers for that particular system? If there is some type of system set rate array through hardware, can you get there and make sure everybody's had that particular case? Also, don't forget that the hard drives in a Raidarray are just like any other hard drives. They're connected properly and make sure they've got power. Now, if a rate stops working, that means it was working. And now it's not raid arrays again, they're just hard drives. So always look at them as you would look at a hard drive. Does the hard drive have power? Is the hard drive plugged in? Has somebody erased something you weren't anticipating? Always go through the mental reinstall, especially with rayrays, and you'll get to the answers pretty quickly. So the rest of these problems that they're talking about, I'm going to call them single drive. I've got a single drive system. We're not doing Raiders or anything wacky. So let's start from the top. What have we got first here? Read, write, and fail. Read and write about your failures. are a big problem with hard drives. All hearts have a certain lifespan to them, and at the end of that lifespan, they start to manifest a certain problem. And read/write failures are a big one. One of the things we can do is we can take advanced technology called smart. It's not smart. It's S-M-A RT. All hard drives contain smart technology, and with the right tools, we can query a drive and get a rough idea of its health. Smart isn't perfect, but it is the only real tool we have. If a drive is starting to act up,well, you can run a smart detector. The bottom line is you're going to do the same thing no matter what. You're going to replace the drive. And did I mention backup? I did. Okay, next slow performance. Now, if I have source on a system, one of the last places I'm going to be blaming any trouble is the actual drive itself. And my best experience If I'm getting slow performance and I can zero in on the mass storage issue, the biggest problem more than anything else is that I don't have any RAM in this system or not enough to be able to make the system run as fast as it should. And I'm going into virtual memory and I'm getting what's known as a disc thrash. The big hint here is that your hard disc drive's little red read-writelight is going absolutely crazy. The answer there There's nothing wrong with mass storage. You just need to get yourself some more RAM. What else? OOH, a loud clicking noise or the great click of death? In the decades I've been working on computers, some form of mass storage device or another that physically breaks the click of death is terminal. There is absolutely no way to get around them if you can get a backup. But again, the answer is to replace the hard drive. Failure to boot.

OK, well, first of all, most failures to boot is because the system has somebody put a thumb drive in or something and you've messed up your boot order. So the first thing I'm going to be looking at is the border correct. If you're actually booting to a device and the boot order is incorrect, I want you to check it out as we talk about the Windows recovery environment. Take a look at the tools that are built into your operating system to help you recover from boot failures. I've not recognized When you see a drive not recognised error, it's usually because the drive has a formatting issue or something similar. Assuming there's no data issues and you don't have anything precious on there, go ahead and just try to reformat the drive.

A drive that's been working well with data on it, you're rarely going to get a drive not recognised error. The only time that might happen is if you're ripping a hard drive from one Windows system and you plug it into another one. Remember, you need to initialise the disc before Windows will recognise it. Okay? and OS could not be found Alright? I discovered that 99.99% of the time in operating systems, you messed up your boot process. I work with national level competitions and one of my favourite competitions I ever created was I had these wonderful systems and all I did was put a thumb drive in the back and all of these super duper technicians. At least half of them I was totally stumped because they didn't look in the back and see that I put a thumbdrive in there and messed up the boot order. Worse comes to worse, you can always go into your system, set it up and double check. Okay? Attempts to boot to an incorrect device Well, that was easy. That is definitely the boot order. Have you noticed that there are a lot of boot order problems? It's because they're all. I can't tell you how much money I have personally made from people screwing up boot orders. Now, continuous foods are rare.

Book Chapter 10 - Essential Peripherals

1. Optical Media

Ah, optical media. These are these wonderful little round discs that are printed with something on one side and all shiny on the other. These discs have been used to store data since around 1980. And although they're fading out today, we still see lots of systems that have optical media drives in them. And for a lot of us, especially system builders, driver discs and other things still come with optical media. So I want to go ahead and cover it in this particular episode. Now, optical media has been around for a long time, since around 1980, and we can basically break it down into three groups. There are CDs, DVDs, and Blu-ray. And I want to COVID all those real quick in this episode. So first of all, let's start with a CD. CD stands for compact disc, and it was originally designed to do nothing more than play music. It stored the music digitally, basically microscopic, tiny little pits, and then nice shiny spots were our ones and zeroes. It was read by a laser and it allowed us to store a ton of ones and zeroes in a very, very small space. Now, optical media in the CD form was originally for music, and it came in two capacities. There were 74 minutes and 80 minutes. We took this concept and we said, "Well, you know what? We can make this store data and come up with something called a CDROM. So I've got a CDROM right here. So you see that term "compact disk." What this is right here is a CDROM. This is a mastered disc that's dispersed.

And this particular one has device drivers for the very late generation Core i9 processor on it. The whole idea behind CDROM was to allow us to store data. So we had to come up with a file system. And that file system was based on a standard called ISO 96-60, which we don't care about. We basically just call it the CD file system, which allows us to take that CD, put it into a CD drive, and then, within Windows, Mac OS, or whatever, we can actually see the folders and files as they were originally mastered. The CDs were great, but we also enjoyed the capability of making our own CDs. And that's where we began to see stuff like CDR, which allows us to do what we called a burn. And we could put whatever we wanted on this. You couldn't erase it, so we could put whatever we wanted on it and then you could have that for yourself. So for backups, things like that, it was really popular. There was another form of CD called CD Read Write, which not only allowed you to burn stuff, but then you could erase it and go ahead and put more data on there. Now, I want to take one quick peek at this CDR because I want to make sure we're aware of something here. So first of all, you have the speed on this one. It says 52 X.

This was based on a multiple of the original CD speed. Then we had the capacity measured both in megabytes and in minutes. So this is a 700 MB download. Back in the old days, speed was a big deal. Today, any optical CD reader is going to be able to run at extremely high speeds. I won't even worry about that stuff anymore. So, CDs were very, very popular for a long time. The only downside was their capacity. So let's really quickly put up a quick table and show the different types of CDs that were available. Back in the day, CDs started the thirst for optical media, but a new technology called DVD really took off with DVD. And by the way, DVD stands for Digital Videodisk because it was originally designed to play movies. Now, these aren't super high-definition movies or anything. It ran at a very low resolution by today's standards. But it did bring something that was very cool, and that was big surround sound. So, DVDs were absolutely fabulous for playing movies. However, just as we did with CDs playing music to data, we came up with the idea of using DVDs to hold data in what we call DVDROM. And I've got one right here. So if you look at this driver disc for my very modern motherboard, you'll see it says DVDROM. DVD-Dvdrom is a mastered form of DVD. You have to make one, and then you make a gazillion copies of it. It's read-only memory.

And even today, DVD is probably the most common type of optical media out there. You'll be hard pressed to come up with a motherboard that doesn't come with the DVD Rom onit, with all your drivers and everything you need to get that motherboard up to speed. Now, DVDs come in a whole bunch of different capacities. In fact, these capacities are a little bit complex. So what I'm going to do is let me put up a little table. When you're looking at this table, I want you to notice something. DVDs came out in what was called dual-layered, meaning literally that on one side you had two layers and you had different lasers that would hit different layers. So you had a dual layer and you also had a double-sided So you'd have a DVD that was silver on both sides. So the original DVD capacity was single sided single layered. And all of these other ones are either double-sided or double-layered or both. Let's take a look. Just like CDs, we had burnable versions of DVDs as well. In fact, it created some real complications. During the life of DVDs, we began to see some really crazy variances. For example, you'll see that this is a burned DVD called DVD Plus R. Then they had a DVD Minus R and a DVD Ram. And all these weird things on the read write, we had the same problem, so if you take a look here, I've got a DVD plus RW and a DVD minus RW. These were actually competing standards that caused havoc back in the day. You would have to get a player that could be compatible with these different standards and it drove us all bananas.

The nice part is that today, any optical media device can read and write any of these different formats. So it's now a moot point. Today, Blu-ray is considered the number one format in terms of capacity to read writable formats. Blurays are designed for high-definition movies. So they originally had Bluray, and now we have Bluray Rom, and then you have Bluray double-sided or single sided, double layer or single layer. But luckily for us, there are only two capacities. Let's go ahead and put those two capacities up on the screen. You even have, for example, here a burnable bluray disk, and there's even a Bluray rewritable called You Ready? bDRE. I don't have one of those on me. So these large capacities, 25 gigabytes and 50 gigabytes, are so big that they're great for playing high definition movies. But for us, in terms of needing to store a lot of stuff for things like drivers and such, you very rarely see those types of discs. So when we're talking about reading all of these disks, what I've got in front of me here is a classic optical medium. This thing is a reader, a burner, it does everything. It's very hard to find any of these anymore that don't do everything. It's pretty much standardized. So there are a couple of things here I want you to take a look at. First of all, let's look at the back. What you're looking at here is just good old SATA. There's a SATA data port, and then there's a SATA power port.

The only downside to these is what I call the calling card. A lot of times I'll be working on a system and I'll drop a piece of optical media in there with some utility or something like that, and I'll unplug and I can't get the optical media out. And that's where this little teeny-tiny hole comes into play. That hole is nothing more. You take a paperclip, spread it open, you shove it in there very carefully, and it pry’s the door open safely. It doesn't hurt anything, and you can get your calling card out. So, yeah, I've done a few calling cards in my day.

So anyway, I want to plug this in. I've got a SATA cable right here, so it's no big deal. Just plug that in just like that. I give it some power, and this thing's ready to go. So when it comes to configuration, because this particular device is an Atria type device, all computers are ready to talk to it. So in this particular case, I've got an anta device here. I've got it plugged in. If I've done this right, it'll show up in the system setup, which it does. I've gone ahead and booted into Windows, and if I've done this right, it should show up in Mismanagement. Let's take a look. And if we take a look right here, there is our optical media device. So the beautiful part about configuring optical media is that today they're all SATAdevices based on the Ata standard. Plug them in, make sure they show up in their system setup, and your operating system is going to see them automatically. It's just that easy.

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