working with hard drives

Author: kpa28-git

Diff for: README.md

@@ -13,23 +13,6 @@ Houses helpful concise information primarily about GNU/Linux, POSIX, and related
 
 I started this a while ago. It is fairly incomplete but we'll see if it grows, not making promises yet.
 
-# Todo
-## Mature
-* linux-fhs
-* package-managers_conda
-* package-managers_pacman+yay
-* package-managers_pip
-
-## Started
-* networking
-* shell_bash
-* shell_posix
-* text-editors_vim
-
-## Empty
-* text-editors_kakoune
-* shell_xonsh
-
 # Guidelines and Structure
 ## Topics
 Each directory is about a particular topic. Each topic may or may not have an associated general category. The naming convention is: '\<General Category\>_\<Specific Topic\>' or simply '\<Specific Topic\>' if there is no associated category. Dashes ('-') are used instead of spaces. If a Specific Topic has an underscore in its name, it is replaced by a dash ('wpa_supplicant' -> 'wpa-supplicant').

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+../mkfs/how.md

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+../mkfs/how.md

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+
+# One Sentence
+The ext4 file system is a modern journalling filesystem that is usually the default
+choice on Linux.
+
+# Background
+The ext4 filesystem is an improvement over ext3, which itself improves on ext2.
+The ext2 filesystem may be useful because it has native support on both FreeBSD
+and Linux. Other than this case, ext4 should generally be preferred.

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+
+## Enter fdisk shell for device `<d>`
+`sudo fdisk /dev/<d>`
+
+## List commands
+`fdisk> m`
+
+## Delete Partition
+`fdisk> d`
+
+## Create GPT Partition Table (Overwrites Existing)
+`fdisk> g`
+
+## Create New Partition
+`fdisk> n`
+
+## Print Partition Table
+`fdisk> p`
+
+## Print Unpartitioned Space
+`fdisk> F`
+
+## Print Partition Information
+`fdisk> i`
+
+## Write and Quit
+`fdisk> w`
+
+## Quit Without Saving
+`fdisk> q`

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+# One Sentence
+The `fdisk` tool lets you create and modify partition tables.
+
+# Background
+See `linux/devices/drives` for background on how drives work in Linux.
+
+The `fdisk` tool is a simple tool letting you create/delete partitions and create
+fresh partitions. Of course, you can also create fresh partition tables with it.
+The GNU `parted` tool can let you manipulate partitions _and_ filesystems,
+but I prefer using `fdisk` and `mkfs`.

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+
+## Format Partition `<p>` (e.g. `sdb1`) to Filesystem `<fs>` (e.g. `ext2`, `ext4`, `exfat`, `ntfs`, etc)
+`$ sudo mkfs.<fs> /dev/<p>`
+
+## Format Partition `<p>` to ext4
+`$ sudo mkfs.ext4 /dev/<p>`
+
+## Format Partition `<p>` to ntfs
+`$ sudo mkfs.ntfs /dev/<p>`
+

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-## Change the label of an NTFS drive partition
-`$ sudo ntfslabel -f /dev/sdb1 NTFS128G-0`
+## Creating NTFS Filesystem at Partition
+See filesystem/mkfs/how.md hpage
+
+## Change the label of an NTFS drive partition `<part>` to <label>
+`$ sudo ntfslabel -f /dev/<part> <label>`
 

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+
+# One Sentence
+The zfs filesystem is an advanced filesystem used natively by FreeBSD.
+
+# Background
+The zfs filesystem is an influential filesystem that may be the most advanced
+free and open source file system available.

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+# Julia
+
+## Run a Shell Command (Create Cmd object and Run it)
+`run(<shell command>)`
+

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+# One Sentence
+In Linux, all drives are files.
+
+# Background
+This section gives a working understanding of how hard drives work on Linux and basic
+information on how to prepare them. Use other hpages or manpages to understand
+how to use the commandline tools described here.
+
+## How Hard Drives work in Linux
+### Device File
+Recall than in the Unix philosophy, everything is a file. Things may not _literally_
+be files, but the point is they should be able to act like them. To the extent they
+follow Unix, Linux and BSD thus also treat everything like files. In these operating
+systems, you have _file abstractions_ like _device files_ and _sockets_. Even though
+these aren't files in the traditional sense, they can be read from and written to,
+just like files.
+
+When you plug in a hard drive in Linux, a _device file_ is created in the `/dev`
+directory. Usually the first hard drive is `/dev/sda`, second is `/dev/sdb`, and so on
+(but not necessarily). You can use the `lsblk` (list block devices) tool to print
+information on what _block devices_ are available.
+
+### Block Device
+A hard drive is one example of a [block device](https://unix.stackexchange.com/questions/259193/what-is-a-block-device).
+A block device is basically something you can read from or write to in "blocks" instead of
+individual characters. It may mean something specific, but for a working understanding
+you can treat block device and hard drive as interchangeable. Note that you can have
+device files that don't point to block devices (`/dev/random` and `/dev/zero` are examples).
+
+### Partition Tables and Partitions
+A hard drive has a partition table, partitions, and filesystems. A partition is basically
+a chunk of a block device. Partitions, like mathematical partitions, cannot overlap with
+each other. Other than logically dividing the hard drive into usable areas, the other
+job of the partition is to hold the filesystem. The filesystem is the interface for you
+to create, modify, and delete files.
+
+A partition table is a single, low-level thing on the disk that describes all the partitions a
+disk has. So the first step to making a disk usable is to create and setup the partition
+table.
+
+### MBR and GPT
+Two different protocols for partition tables are master boot record (MBR) and
+grand partition table (GPT). I don't know the difference between them, but basically
+they can each support different filesystems and features. MBR is the older one and
+GPT is the newer one. You usually want to use GPT unless you need to use MBR for some
+reason (using some kind of DOS drive).
+
+### Filesystems
+To actually use a partition, it needs a filesytem. A filesystem is the interface
+that is used to manage files. Many filesystems exist, each with different features,
+for example `ext4` is commonly used on Linux and `zfs` is commonly used on FreeBSD.
+
+## How to Use Drives
+### Creation
+The `fdisk` tool is a simple tool letting you create/delete partitions and create
+fresh partitions. Of course, you can also create fresh partition tables with it.
+Use `mkfs` to make new filesystems on partitions.
+
+The GNU `parted` tool is another tool that can help you repartition a drive and
+create filesystems. I prefer using the separete `fdisk` and `mkfs` tools though.
+
+### Mounting
+In order to use a partition, it has to be _mounted_ to the filesystem.
+Mounting is kind of like the docking procedure on a space ship. It's where
+the two systems "connect" and can then transfer things between them.
+Use the `mount` and `umount` commands to mount partitions to particular
+(empty) directories and also unmount them, respectively.
+