# Knowing Knoppix/Knoppix essentials

## Knoppix essentials

*"If I ever met Bill Gates, there wouldn\'t be much of a meeting point.
I couldn\'t tell him about business, and he couldn\'t tell me about
technology." \-- Linus Torvalds*

This section contains important background information that will help
you understand the rest of this book. If you are in a hurry, skip over
this section. The terms explained in this section will be used often, so
you may need to refer back to this page later.

### File names

The following rules apply to file names in *Knoppix*.

-   **Case sensitive.** This causes the most problems for beginners. For
    example, "myfile.txt", "MyFile.txt" and "**MYFILE.TXT**" are all
    different names.
-   **Long file names are allowed.** File names can be up to 255
    characters long.
-   **There is no "C:" drive.** Instead, all files are arranged in a
    tree beginning with "/", which is called the *root
    directory*. The "root directory" is
    like "My Computer". It is the starting point for everything stored
    inside in the computer.
-   **Forward slashes.** For example, in Windows, part of the location
    of an image file might be:\
    `My Documents\My Pictures\duck.jpg`\
    In *Knoppix*, the backslashes that represent the path to the file
    are written as forward slashes instead, like this:\
    `My Documents/My Pictures/duck.jpg`

**`Note`**\
`What's the difference between a directory and a folder? Not much.`\
`A folder is just the icon that is usually used to represent a directory.`\
`The words “directory” and “folder” are `*`interchangeable`*`.`\
`Remember, a hard disk is like a filing cabinet.`\
`Partitions are like drawers, directories are like folders, and files are like individual documents.`

### Drive names

You may be used to Microsoft Windows\' naming scheme for disk drives.
For example, you may be used to "drive A:" for the first floppy drive;
"drive C:" for the first visible hard drive partition, and so on.
Knoppix has its own drive naming scheme. This section explains how the
naming scheme works.

#### Disk types

The naming scheme starts with a two-letter code for the type of disk.

  Name   Drive type
  ------ ----------------------------------------------
  fd     Conventional floppy drive
  hd     Integrated Drive Electronics (IDE) drive
  sd     Small Computer System Interface (SCSI) drive

#### IDE drives

IDE drives are the most common in desktop PCs
and laptops. A single letter indicates how the drive is connected. Most
PCs and laptops have two IDE *channels*: primary
and secondary. Each channel can have up to two
devices: master and slave.

  Name   IDE drive
  ------ ------------------
  hda    Primary Master
  hdb    Primary Slave
  hdc    Secondary Master
  hdd    Secondary Slave

#### SCSI drives

For SCSI drives, a single letter indicates
its location. This is called its position in the *SCSI chain*. Zip, USB
and Firewire drives are also treated as SCSI drives.

  Name   SCSI drive location
  ------ ---------------------
  sda    First SCSI drive
  sdb    Second SCSI drive
  sdc    Third SCSI drive

#### Disk partitions

IDE and SCSI hard drives are divided into *partitions*. Zip, USB and
Firewire drives also contain partitions. A
partition is like a compartment within a disk. There may be a single
partition that covers the entire disk. There may be more than one
partition. Each partition is indicated by a number.

  Name   Drive                      Partition
  ------ -------------------------- ------------------
  hda1   Primary master IDE drive   First partition
  hda2   Primary master IDE drive   Second partition
  hda3   Primary master IDE drive   Third partition

#### SCSI emulation for IDE CD-ROM drives

IDE CD-ROM drives are treated as SCSI drives. This is called *SCSI
emulation*. SCSI emulation is there so that CD burning applications can
use the same language to talk to SCSI and IDE drives.

  Name   CD-ROM drive
  ------ ---------------------
  scd0   First CD-ROM drive
  scd1   Second CD-ROM drive
  scd2   Third CD-ROM drive

#### Conventional 1.44 Mb floppy drives

For ordinary floppy disk drives, a number
shows the drive number.

  Name   Floppy drive number
  ------ ---------------------
  fd0    First floppy drive
  fd1    Second floppy drive

### Drive detection

Knoppix automatically detects all IDE and SCSI
devices. The names of the devices are printed in the startup messages
(Ctrl+Alt+F1). Here is an example:

`hda: [FUJITSU MPA3026AT]`\
`hdb: [LS-120 VER5 00 UHD FLOPPY]`\
`hdc: [HITACHI DVD-ROM GD-2500]`\
`hdd: [MATSHITA CD-RW CD-7586]`

This example shows that the primary master is a Fujitsu hard drive. The
primary slave is an Imation LS-120 SuperDisk drive. The secondary master
is a Hitachi DVD-ROM drive. The secondary slave is a Matshita CD-RW
drive.

### Partition detection

*Knoppix* automatically detects all
partitions on all IDE and SCSI devices. For
example, given a single Windows partition on the primary master IDE hard
drive, the following *device name* will be created:

`/dev/hda1`

This means the partition will be called /dev/hda1 in Knoppix.

**`Note`**\
`Some removable disks also have partitions, notably Iomega Zip disks.`\
`For the partitions on an Iomega Zip disk to be detected properly, you must insert the disk into the drive before you start Knoppix.`

### Mount points

Each device name has a *mount point*. This
is a special place where the files on a device appear. A mount point is
created automatically for each device name. For example, given the
Fujitsu drive above, the following mount point will be created:

`/mnt/hda1`

This means the partition /dev/hda1 will be mounted to /mnt/hda1.

#### Auto-mounting of floppy and CD-ROM drives

Conventional floppy and CD-ROM drives are
*auto-mounted*. This means Knoppix takes care
of mounting and unmounting them automatically. The auto-mount locations
are:

-   First floppy drive: /mnt/floppy
-   Second floppy drive: /mnt/floppy1
-   First CD-ROM drive: /mnt/cdrom
-   Second CD-ROM drive: /mnt/cdrom1

### Login accounts

When you start Knoppix, you are logged in automatically. No
passwords are needed. All passwords are locked
by default. Knoppix bypasses all the usernames and passwords of the
operating system installed on the hard disk.

  Keyboard shortcut   Virtual terminal                                        Logged in as user account
  ------------------- ------------------------------------------------------- ---------------------------
  Ctrl+Alt+F1         Console number 1                                        root
  Ctrl+Alt+F2         Console number 2                                        root
  Ctrl+Alt+F3         Console number 3                                        root
  Ctrl+Alt+F4         Console number 4                                        root
  Ctrl+Alt+F5         X Window System (KDE)   knoppix

You can switch between the virtual terminals at any time. For example,
to switch to the first console, press Ctrl+Alt+F1. The Knoppix startup
messages will be displayed. To switch to the second console, press
Ctrl+Alt+F2. To get back to the X Window System, press Ctrl+Alt+F5.

**`Note`**\
`The X Window System is on virtual terminal number 5.`

### User accounts

#### The user account

The Knoppix *user* account is called "*knoppix*".
This account is for all productivity tasks, including CD burning and
printing. When the X Window System starts, you are logged in to that
user account automatically, without a password.

#### The superuser account

The *superuser* account is for system
administration tasks. The superuser account is called the *root
account*. When *Knoppix* starts, you are logged in as
*root* to all four consoles automatically with no
password. It is also possible to use the root account within the X
Window System.

**`Important`**\
`As with other Linux distributions, use the `*`user`*` account for all your everyday tasks.`\
`Only use the `*`root`*` account when you need it.`\
` For example, when you are logged on as `*`root`*`, you have the power to instantly delete every file on every disk with one simple command.`\
`When you are logged on as a `*`user`*`, the system will not let you do that. This helps you to protect yourself against accidents.`\
`Get into the habit now and it will save you later!`

