1 00:00:00,420 --> 00:00:02,009 In this lesson, we're going to talk 2 00:00:02,009 --> 00:00:03,780 about Linux devices. 3 00:00:03,780 --> 00:00:05,010 Now, at some point, 4 00:00:05,010 --> 00:00:07,530 you're going to need physical hardware to interface 5 00:00:07,530 --> 00:00:09,390 with the Linux operating system, 6 00:00:09,390 --> 00:00:12,600 even if you're not co-located with the system itself. 7 00:00:12,600 --> 00:00:15,600 Therefore, you need to ensure that any hardware devices 8 00:00:15,600 --> 00:00:17,040 that are connected to the system 9 00:00:17,040 --> 00:00:19,590 are going to be recognizable to that system, 10 00:00:19,590 --> 00:00:21,600 and they're properly configured. 11 00:00:21,600 --> 00:00:24,150 So, in this lesson, you're going to learn how 12 00:00:24,150 --> 00:00:26,790 to manage several different kinds of devices. 13 00:00:26,790 --> 00:00:28,770 Now, before you begin using Linux commands 14 00:00:28,770 --> 00:00:31,650 to manage these devices or apply your skills and knowledge 15 00:00:31,650 --> 00:00:34,170 in a Linux environment, though, you need to become familiar 16 00:00:34,170 --> 00:00:37,470 with the different types of devices that Linux supports. 17 00:00:37,470 --> 00:00:39,480 I'm going to help you build a solid understanding 18 00:00:39,480 --> 00:00:41,250 of what common devices are, 19 00:00:41,250 --> 00:00:43,710 and how they connect to your different computers. 20 00:00:43,710 --> 00:00:46,740 As you know, device drivers act as an interface 21 00:00:46,740 --> 00:00:49,830 between the operating system and the hardware devices. 22 00:00:49,830 --> 00:00:53,070 Drivers are crucial for devices to function properly, 23 00:00:53,070 --> 00:00:56,460 or even to function at all within your Linux environment. 24 00:00:56,460 --> 00:00:59,070 Now, there are different types of client devices. 25 00:00:59,070 --> 00:01:00,990 If you have a thin client, for instance, 26 00:01:00,990 --> 00:01:03,120 this is any lightweight computing device 27 00:01:03,120 --> 00:01:04,980 that connects to a more powerful server 28 00:01:04,980 --> 00:01:06,870 for doing all of the heavy work. 29 00:01:06,870 --> 00:01:09,570 That server is going to do all the heavy lifting for you, 30 00:01:09,570 --> 00:01:11,850 including processing and storing the data, 31 00:01:11,850 --> 00:01:14,160 while the thin client acts as little more 32 00:01:14,160 --> 00:01:16,110 than a user interface for you. 33 00:01:16,110 --> 00:01:17,880 This type of computing architecture 34 00:01:17,880 --> 00:01:19,890 is going to centralize your operations, 35 00:01:19,890 --> 00:01:22,320 making it easier for administrators to manage groups 36 00:01:22,320 --> 00:01:24,300 of backend servers, instead of all 37 00:01:24,300 --> 00:01:25,770 the individual workstations 38 00:01:25,770 --> 00:01:28,050 that are dispersed throughout the organization. 39 00:01:28,050 --> 00:01:29,100 Now, as you've seen, 40 00:01:29,100 --> 00:01:32,280 Linux has a robust remote connection support capability. 41 00:01:32,280 --> 00:01:34,980 Whether that's through a GUI with remote desktop apps, 42 00:01:34,980 --> 00:01:37,950 or through a terminal using Secure Shell. 43 00:01:37,950 --> 00:01:40,860 Now, a thin client will typically have basic devices 44 00:01:40,860 --> 00:01:44,130 like a keyboard, a mouse, and a monitor connected to it, 45 00:01:44,130 --> 00:01:45,450 and it could be running Linux 46 00:01:45,450 --> 00:01:48,180 or it could be running something else like Windows. 47 00:01:48,180 --> 00:01:50,070 If it is running Linux, it's typically 48 00:01:50,070 --> 00:01:52,140 going to be a lightweight distribution 49 00:01:52,140 --> 00:01:54,030 with very few features available, 50 00:01:54,030 --> 00:01:56,520 or anything really permissible to the user. 51 00:01:56,520 --> 00:01:59,550 Instead, that thin client is just used to connect 52 00:01:59,550 --> 00:02:01,110 to the remote Linux server, 53 00:02:01,110 --> 00:02:03,060 where you're going to do all your work. 54 00:02:03,060 --> 00:02:05,730 Now, universal serial bus, or USB, 55 00:02:05,730 --> 00:02:07,830 is a peripheral interface technology 56 00:02:07,830 --> 00:02:09,870 that has become the defacto standard 57 00:02:09,870 --> 00:02:12,270 for connecting all your different input devices, 58 00:02:12,270 --> 00:02:14,850 your external storage devices, your mobile devices, 59 00:02:14,850 --> 00:02:18,390 and many other things to your computers and thin clients. 60 00:02:18,390 --> 00:02:20,820 Now, USB also incorporates something known 61 00:02:20,820 --> 00:02:22,890 as plug and play technologies. 62 00:02:22,890 --> 00:02:25,800 This enables devices to self-configure themself 63 00:02:25,800 --> 00:02:28,080 as soon as you plug them into the system. 64 00:02:28,080 --> 00:02:31,020 Now, there are a wide range of USB device types out there, 65 00:02:31,020 --> 00:02:33,390 and a lot of these are supported in Linux. 66 00:02:33,390 --> 00:02:36,660 This includes things like thumb drives, external hard drives 67 00:02:36,660 --> 00:02:40,590 and solid state devices, digital cameras, webcams, 68 00:02:40,590 --> 00:02:45,590 smartphones, tablets, printers, scanners, keyboards, mice, 69 00:02:46,230 --> 00:02:49,590 microphones, game controllers, and many others. 70 00:02:49,590 --> 00:02:53,160 When you plug in that USB device, Linux is going to register 71 00:02:53,160 --> 00:02:55,560 these USB storage devices that are attached 72 00:02:55,560 --> 00:03:00,560 to the system in the same format as /dev/sd with a number, 73 00:03:00,840 --> 00:03:02,430 just like as if you were connecting it 74 00:03:02,430 --> 00:03:05,970 through an ATA interface or a SCSI interface. 75 00:03:05,970 --> 00:03:09,180 The next thing we want to talk about is wireless devices. 76 00:03:09,180 --> 00:03:11,400 Now, wireless devices are used to transmit 77 00:03:11,400 --> 00:03:13,500 and receive signals over the air, 78 00:03:13,500 --> 00:03:14,820 instead of sending those signals 79 00:03:14,820 --> 00:03:18,360 over physical cables that are connected directly to a port. 80 00:03:18,360 --> 00:03:20,040 There are many different wireless networking 81 00:03:20,040 --> 00:03:22,500 protocols out there, and each of these are used 82 00:03:22,500 --> 00:03:25,410 for specific things or specific applications. 83 00:03:25,410 --> 00:03:27,300 For example, there are lots of different 84 00:03:27,300 --> 00:03:29,100 common wireless networking protocols 85 00:03:29,100 --> 00:03:32,700 that are supported by Linux, including wifi, Bluetooth, 86 00:03:32,700 --> 00:03:35,580 and NFC or near field communication. 87 00:03:35,580 --> 00:03:38,370 Now, wifi is a technology used primarily 88 00:03:38,370 --> 00:03:41,340 for establishing a wireless local area network connection, 89 00:03:41,340 --> 00:03:43,590 or a WLAN connection, inside your home 90 00:03:43,590 --> 00:03:45,390 or office environments. 91 00:03:45,390 --> 00:03:47,910 Common devices that you're going to use with wifi 92 00:03:47,910 --> 00:03:50,490 are things like wireless routers and access points 93 00:03:50,490 --> 00:03:52,170 for the networking infrastructure. 94 00:03:52,170 --> 00:03:54,900 You also have mobile devices, desktop computers, 95 00:03:54,900 --> 00:03:56,520 and "internet of things" devices 96 00:03:56,520 --> 00:03:58,980 that are going to act as wifi clients. 97 00:03:58,980 --> 00:04:00,480 If you're using Bluetooth, 98 00:04:00,480 --> 00:04:02,520 this is a technology that's primarily used 99 00:04:02,520 --> 00:04:05,730 for establishing a personal area network, or PAN, 100 00:04:05,730 --> 00:04:08,160 in which your devices can communicate wirelessly 101 00:04:08,160 --> 00:04:09,930 within a few feet of each other. 102 00:04:09,930 --> 00:04:11,820 The most common application for this 103 00:04:11,820 --> 00:04:13,890 is to be able to connect wireless headphones 104 00:04:13,890 --> 00:04:16,500 or headsets, or a keyboard or mouse 105 00:04:16,500 --> 00:04:19,200 to a smartphone or other computing device. 106 00:04:19,200 --> 00:04:20,459 This will allow you to do this 107 00:04:20,459 --> 00:04:23,220 without having any kind of cabling attached. 108 00:04:23,220 --> 00:04:26,490 On the other hand, we might also use things like NFC, 109 00:04:26,490 --> 00:04:28,470 which is near field communication. 110 00:04:28,470 --> 00:04:29,970 Now, near field communication 111 00:04:29,970 --> 00:04:32,190 is a specialized communications protocol 112 00:04:32,190 --> 00:04:35,580 that's really used mostly by mobile devices and peripherals. 113 00:04:35,580 --> 00:04:37,920 And these are going to be things that are going to send data 114 00:04:37,920 --> 00:04:41,070 when they're only within a couple of inches of each other. 115 00:04:41,070 --> 00:04:43,320 NFC, for example, is used heavily 116 00:04:43,320 --> 00:04:46,410 inside the payment industry, where you can tap a credit card 117 00:04:46,410 --> 00:04:49,890 on top of a reader, or tap a smartphone on top of a reader 118 00:04:49,890 --> 00:04:52,410 to collect payment from an individual. 119 00:04:52,410 --> 00:04:53,820 Now, another thing we want to talk about 120 00:04:53,820 --> 00:04:55,740 is video and audio devices. 121 00:04:55,740 --> 00:04:59,250 Now, video and audio devices are input or output peripherals 122 00:04:59,250 --> 00:05:00,450 that are usually going to be attached 123 00:05:00,450 --> 00:05:02,400 to a client system like a desktop 124 00:05:02,400 --> 00:05:05,130 or a laptop, or even a thin client. 125 00:05:05,130 --> 00:05:06,630 Now, there are a lot of different audio 126 00:05:06,630 --> 00:05:08,370 and video peripherals out there. 127 00:05:08,370 --> 00:05:10,470 When we think about video input peripherals, 128 00:05:10,470 --> 00:05:12,330 this can include things like a webcam, 129 00:05:12,330 --> 00:05:15,060 a surveillance camera, or a digital camera. 130 00:05:15,060 --> 00:05:17,040 When you're thinking about an output peripheral, 131 00:05:17,040 --> 00:05:18,630 this would be something like a monitor, 132 00:05:18,630 --> 00:05:20,760 a television, or a projector. 133 00:05:20,760 --> 00:05:22,020 When we talk about audio, 134 00:05:22,020 --> 00:05:24,510 the most common input is going to be a microphone, 135 00:05:24,510 --> 00:05:25,710 and the most common output 136 00:05:25,710 --> 00:05:28,230 is going to be a speaker or headphones. 137 00:05:28,230 --> 00:05:30,270 When you connect a video or audio peripheral 138 00:05:30,270 --> 00:05:33,540 to a system running Linux or any other OS, for that matter, 139 00:05:33,540 --> 00:05:35,400 you need to make sure you understand the different types 140 00:05:35,400 --> 00:05:36,990 of connections that it uses, 141 00:05:36,990 --> 00:05:39,660 and what types are available on that system. 142 00:05:39,660 --> 00:05:42,210 For example, if you go and buy a microphone, 143 00:05:42,210 --> 00:05:43,950 its input into your system 144 00:05:43,950 --> 00:05:48,420 could either be over a USB or a 1/8 inch input jack 145 00:05:48,420 --> 00:05:50,520 that's going to be used only for audio. 146 00:05:50,520 --> 00:05:52,320 Depending on which one your system has, 147 00:05:52,320 --> 00:05:53,520 it's going to make a difference 148 00:05:53,520 --> 00:05:56,190 on which type of microphone you actually buy. 149 00:05:56,190 --> 00:05:58,380 Now, monitors, for example, are going to be used 150 00:05:58,380 --> 00:06:01,369 as an output device, and you can use things like HDMI, 151 00:06:01,369 --> 00:06:05,250 display port, DVI, or VGA. 152 00:06:05,250 --> 00:06:06,450 All of these are different types 153 00:06:06,450 --> 00:06:08,310 that can be used for video output. 154 00:06:08,310 --> 00:06:10,950 So, it's important to know which one is on your computer 155 00:06:10,950 --> 00:06:12,180 when you're buying a monitor, 156 00:06:12,180 --> 00:06:14,550 so you have one that will work for you. 157 00:06:14,550 --> 00:06:16,830 Now, like most other operating systems, 158 00:06:16,830 --> 00:06:19,560 Linux will also provide you with support for printers. 159 00:06:19,560 --> 00:06:21,870 Now, support for a specific type of printer 160 00:06:21,870 --> 00:06:23,520 is going to be dependent on whether or not 161 00:06:23,520 --> 00:06:26,280 there's an available driver for Linux to be able to use 162 00:06:26,280 --> 00:06:30,120 for that printer, and how robust those drivers are. 163 00:06:30,120 --> 00:06:31,620 So, before you buy a printer, 164 00:06:31,620 --> 00:06:34,440 you need to make sure it's going to be supported by Linux. 165 00:06:34,440 --> 00:06:36,270 Now, most modern printers will offer 166 00:06:36,270 --> 00:06:39,180 local connection support through a USB interface, 167 00:06:39,180 --> 00:06:41,250 or if you're in an office environment, 168 00:06:41,250 --> 00:06:43,860 you may be able to connect to it over the network. 169 00:06:43,860 --> 00:06:46,650 In that case, the printer may include a wifi adapter 170 00:06:46,650 --> 00:06:49,050 built in, or an ethernet adapter, 171 00:06:49,050 --> 00:06:51,750 so it can be connected to the local area network. 172 00:06:51,750 --> 00:06:53,130 Now, another thing we need to talk about 173 00:06:53,130 --> 00:06:54,750 is network adapters. 174 00:06:54,750 --> 00:06:56,550 Network adapters are going to be mandatory 175 00:06:56,550 --> 00:06:58,770 for any computing device that wants to be able 176 00:06:58,770 --> 00:07:01,560 to access a network, whether that's your local office 177 00:07:01,560 --> 00:07:04,950 network, or a wider network, like the internet. 178 00:07:04,950 --> 00:07:06,510 Now, a network interface card 179 00:07:06,510 --> 00:07:09,210 is a specialized peripheral device that can provide you 180 00:07:09,210 --> 00:07:10,950 with an interface with a host 181 00:07:10,950 --> 00:07:14,160 where that computer can exchange data over the network. 182 00:07:14,160 --> 00:07:16,080 In most cases, network adapters 183 00:07:16,080 --> 00:07:18,570 are already built into your computer's motherboard. 184 00:07:18,570 --> 00:07:21,180 However, some adapters can be added to the system 185 00:07:21,180 --> 00:07:23,790 on an expansion bus, or by using something 186 00:07:23,790 --> 00:07:25,920 like a USB device. 187 00:07:25,920 --> 00:07:28,950 Another thing we want to talk about is GPIO, 188 00:07:28,950 --> 00:07:31,890 which refers to the general purpose input output. 189 00:07:31,890 --> 00:07:34,290 And this refers to the pins on a circuit board 190 00:07:34,290 --> 00:07:35,940 that have no designated purpose, 191 00:07:35,940 --> 00:07:39,450 but they're controllable by the user at runtime. 192 00:07:39,450 --> 00:07:42,120 These pins can send and receive digital signals, 193 00:07:42,120 --> 00:07:45,240 and they can be either in on-state or in off-state. 194 00:07:45,240 --> 00:07:47,640 For example, you might have one of these pins 195 00:07:47,640 --> 00:07:49,290 that's designated as an output, 196 00:07:49,290 --> 00:07:51,330 and therefore, it can turn an LED light 197 00:07:51,330 --> 00:07:54,150 on or off, based on the signal received. 198 00:07:54,150 --> 00:07:56,790 Or you can have a pin designated as input, 199 00:07:56,790 --> 00:07:59,250 and it can be used to turn on or off a device, 200 00:07:59,250 --> 00:08:00,540 something like a light switch 201 00:08:00,540 --> 00:08:03,030 or a reset button on the computer. 202 00:08:03,030 --> 00:08:06,510 In most cases, GPIO functionality is going to be controlled 203 00:08:06,510 --> 00:08:08,490 programmatically through software. 204 00:08:08,490 --> 00:08:11,340 On your motherboard, for instance, any GPIO ports 205 00:08:11,340 --> 00:08:14,100 you have will usually be indicated and controlled 206 00:08:14,100 --> 00:08:16,560 by your BIOS or your UFI. 207 00:08:16,560 --> 00:08:19,710 Another thing we want to talk about is serial AT attachment, 208 00:08:19,710 --> 00:08:21,630 or serial ATA. 209 00:08:21,630 --> 00:08:24,450 Now, ATA is a computer bus interface 210 00:08:24,450 --> 00:08:26,730 that's a standard for attaching storage devices 211 00:08:26,730 --> 00:08:28,500 to traditional computers. 212 00:08:28,500 --> 00:08:31,410 In modern computers, SATA has largely replaced 213 00:08:31,410 --> 00:08:33,900 the earlier standard known as parallel ATA, 214 00:08:33,900 --> 00:08:38,250 or PATA, and integrated drive electronics or IDE. 215 00:08:38,250 --> 00:08:40,770 For this reason, most people are going to use SATA 216 00:08:40,770 --> 00:08:42,929 for your internal hard drives. 217 00:08:42,929 --> 00:08:45,540 Now, the most current revision at the time of this recording 218 00:08:45,540 --> 00:08:49,200 is SATA revision 3.2, and this combines SATA 219 00:08:49,200 --> 00:08:53,010 with another bus technology known as PCI Express. 220 00:08:53,010 --> 00:08:56,610 This allows us to support really fast data transfer rates; 221 00:08:56,610 --> 00:08:59,010 up to 16 gigabits per second. 222 00:08:59,010 --> 00:09:01,560 And this means it is a very fast way to send data 223 00:09:01,560 --> 00:09:05,520 to and from a hard drive, and to or from your CPU. 224 00:09:05,520 --> 00:09:08,970 Now, SATA is primarily used for attaching storage devices, 225 00:09:08,970 --> 00:09:10,620 like internal hard drives. 226 00:09:10,620 --> 00:09:12,747 But we have another thing out there known as SCSI, 227 00:09:12,747 --> 00:09:16,200 and SCSI is the small computer system interface. 228 00:09:16,200 --> 00:09:18,030 It's a computer bus interface 229 00:09:18,030 --> 00:09:21,420 for connecting peripheral devices to traditional computers. 230 00:09:21,420 --> 00:09:24,750 Now, SCSI can be used to attach other types of devices too, 231 00:09:24,750 --> 00:09:26,400 in addition to hard drives. 232 00:09:26,400 --> 00:09:29,700 It can be used for DVD ROMs, printers, scanners, 233 00:09:29,700 --> 00:09:31,170 and other things like that. 234 00:09:31,170 --> 00:09:34,020 But most commonly, we use it for storage. 235 00:09:34,020 --> 00:09:36,240 Now, SCSI is an older technology, 236 00:09:36,240 --> 00:09:39,810 but if you're using Linux servers, you may come across it. 237 00:09:39,810 --> 00:09:41,370 Another thing we want to talk about 238 00:09:41,370 --> 00:09:44,760 is serial attached SCSI, which is SAS. 239 00:09:44,760 --> 00:09:46,380 And this is a standard that was developed 240 00:09:46,380 --> 00:09:49,620 to apply a serial interface to SCSI technology. 241 00:09:49,620 --> 00:09:51,840 This allows us to have faster speeds 242 00:09:51,840 --> 00:09:53,880 and a more modern version of SCSI. 243 00:09:53,880 --> 00:09:57,810 In fact, when you're using SAS, or Serial Attached SCSI, 244 00:09:57,810 --> 00:10:01,080 you can reach speeds of up to 24 gigabits per second 245 00:10:01,080 --> 00:10:03,933 in your most modern versions, which is SAS4. 246 00:10:04,770 --> 00:10:08,130 This also supports higher capacity drives. 247 00:10:08,130 --> 00:10:10,800 Another thing we want to talk about is HBA, 248 00:10:10,800 --> 00:10:12,870 or the host bus adapter. 249 00:10:12,870 --> 00:10:15,480 The host bus adapter is a hardware component 250 00:10:15,480 --> 00:10:18,180 that connects a host system to a storage device, 251 00:10:18,180 --> 00:10:20,910 like a storage area network or SAN. 252 00:10:20,910 --> 00:10:23,970 This allows us to facilitate the input and outputted data 253 00:10:23,970 --> 00:10:25,890 to the storage area network. 254 00:10:25,890 --> 00:10:28,470 Now, host bus adapters are commonly used 255 00:10:28,470 --> 00:10:31,770 with the interface technologies like SATA and SCSI, 256 00:10:31,770 --> 00:10:33,360 and the host bus adapter 257 00:10:33,360 --> 00:10:35,640 might be built into your motherboard directly, 258 00:10:35,640 --> 00:10:38,070 or it could be a separate expansion card 259 00:10:38,070 --> 00:10:39,570 that's going to attach to the motherboard 260 00:10:39,570 --> 00:10:41,520 using an expansion slot. 261 00:10:41,520 --> 00:10:44,310 Either way though, you can connect a storage device 262 00:10:44,310 --> 00:10:46,830 to an HBA with the requisite interface 263 00:10:46,830 --> 00:10:49,650 in order for the system to work with that storage device, 264 00:10:49,650 --> 00:10:50,483 and that's going to allow you 265 00:10:50,483 --> 00:10:53,250 to start transferring data the way you want to. 266 00:10:53,250 --> 00:10:54,810 Another type of bus we have 267 00:10:54,810 --> 00:10:59,160 is known as PCI or peripheral component interconnect. 268 00:10:59,160 --> 00:11:01,500 PCI is a connection interface standard 269 00:11:01,500 --> 00:11:03,870 that's primarily used for expansion buses 270 00:11:03,870 --> 00:11:05,220 inside of your motherboard, 271 00:11:05,220 --> 00:11:08,010 like you learned about back in your A+ studies. 272 00:11:08,010 --> 00:11:11,670 Now, the initial PCI specification has largely been replaced 273 00:11:11,670 --> 00:11:16,230 by the more recent PCI express, or PCIe as it's written. 274 00:11:16,230 --> 00:11:19,110 PCIe supports greater transfer speeds, 275 00:11:19,110 --> 00:11:22,320 more reliable error detection, and it's physically smaller 276 00:11:22,320 --> 00:11:24,420 than a traditional PCI slot. 277 00:11:24,420 --> 00:11:27,990 In modern computers, PCIe is going to be the dominant 278 00:11:27,990 --> 00:11:30,840 expansion bus technology that you're going to come across. 279 00:11:30,840 --> 00:11:33,000 When it comes to non-storage devices, 280 00:11:33,000 --> 00:11:36,390 many of these things are going to be using PCIe. 281 00:11:36,390 --> 00:11:39,000 For example, if you want to put an extra modem in, 282 00:11:39,000 --> 00:11:41,820 or a serial card, or a network adapter, 283 00:11:41,820 --> 00:11:45,330 those will all go in through a PCIe expansion bus. 284 00:11:45,330 --> 00:11:47,100 It's also common for video cards 285 00:11:47,100 --> 00:11:50,550 to connect using PCIE x16 interfaces, 286 00:11:50,550 --> 00:11:52,770 to be able to give you a very robust graphics 287 00:11:52,770 --> 00:11:54,693 card that's dedicated to that system.