Improve organization on all docs

Author: ksobrenat32

docs/backup/README.md

@@ -0,0 +1,225 @@
+# Backup Notes
+
+## Utilities
+
+### Tar
+
+Tar is great for creating archives of multiple directories or files into a single file.
+ It also supports compression and can be combined with other tools for encryption
+ and integrity checks.
+
+
+#### Usage
+
+**Compressing directories into a .txz archive:**
+
+```sh
+tar -cJf file.txz /path/to/directorie/1 /path/to/directorie/2
+```
+
+- Use "-J" to use the xz protocol.
+- Use "-cf" to create a new file.
+
+**Using multithreading compression:**
+
+```sh
+tar -cf - /path/to/directorie/1 /path/to/directorie/2 | xz -z -T0 -9 > file.txz
+```
+
+- "-T0" uses all available CPU cores.
+- "-9" is the maximum compression level.
+
+**Extracting an archive:**
+
+```sh
+tar -xJf file.txz
+```
+
+### GPG
+
+GPG can be used to encrypt files for secure storage or transfer.
+
+
+#### Usage
+
+**Create a keypair:**
+
+```sh
+gpg --full-generate-key
+```
+
+**Get key information:**
+
+```sh
+gpg --list-keys
+```
+
+For the key ID, use the long format (16 characters).
+
+```sh
+gpg --list-keys --keyid-format LONG
+```
+
+**Export public key:**
+
+```sh
+gpg --export --armor <recipient_key_id> > publickey.asc
+```
+
+**Import public key:**
+
+```sh
+gpg --import publickey.asc
+```
+
+**Export secret key for backup:**
+
+```sh
+gpg -o private-backup.gpg --export-options backup --export-secret-keys <email_or_key_id>
+```
+
+**Import the backup key:**
+
+```sh
+gpg --import-options restore --import private-backup.gpg
+
+gpg --edit-key username@example.com
+
+> trust
+> 5 (ultimately)
+> save
+```
+
+**Encrypt a file with a recipient**
+
+```sh
+gpg --encrypt --recipient <recipient_key_id> file
+```
+
+**Decrypt a file**
+
+```sh
+gpg --decrypt file.gpg > file
+```
+
+**Encrypt a file with password**
+
+```sh
+gpg --encrypt --symmetric file
+```
+
+### Rsync
+
+Rsync is a powerful tool for synchronizing files and directories between two locations,
+ either locally or over a network.
+
+#### Usage
+
+```sh
+rsync -arzuvhP /path/to/source /path/to/destiny
+```
+
+- "a" for archive mode
+- "r" for recursive
+- "z" for compression on transit (useful in network)
+- "u" for skipping files newer on receiver
+- "v" for verbose
+- "h" for human readable
+- "P" for progress
+
+- "c" for checksum
+- "i" for showing changes in a verbose mode
+
+- "--ignore-existing" for leaving untouched the files on destination
+- "-delete" for deleting files on destination
+
+> "-n" for dry run
+
+When using -i (--itemize-changes) the output of the changes will be
+ more verbose of why the changes are being done, running it with
+ --dry-run is a secure practice in case you want to use -delete, the
+ output description is:
+
+```sh
+YXcstpoguax  path/to/file
+|||||||||||
+`----------- the type of update being done::
+ ||||||||||   <: file is being transferred to the remote host (sent).
+ ||||||||||   >: file is being transferred to the local host (received).
+ ||||||||||   c: local change/creation for the item, such as:
+ ||||||||||      - the creation of a directory
+ ||||||||||      - the changing of a symlink,
+ ||||||||||      - etc.
+ ||||||||||   h: the item is a hard link to another item (requires --hard-links).
+ ||||||||||   .: the item is not being updated (though it might have attributes that are being modified).
+ ||||||||||   *: means that the rest of the itemized-output area contains a message (e.g. "deleting").
+ ||||||||||
+ `---------- the file type:
+  |||||||||   f for a file,
+  |||||||||   d for a directory,
+  |||||||||   L for a symlink,
+  |||||||||   D for a device,
+  |||||||||   S for a special file (e.g. named sockets and fifos).
+  |||||||||
+  `--------- c: different checksum (for regular files)
+   ||||||||     changed value (for symlink, device, and special file)
+   `-------- s: Size is different
+    `------- t: Modification time is different
+     `------ p: Permission are different
+      `----- o: Owner is different
+       `---- g: Group is different
+        `--- u: The u slot is reserved for future use.
+         `-- a: The ACL information changed
+```
+
+### Btrfs
+
+Btrfs is a modern filesystem that supports advanced features like snapshots,
+subvolumes, and built-in RAID support. It is well-suited for backup solutions
+due to its snapshot capabilities and efficient storage management.
+
+#### Usage
+
+**Format a partition with Btrfs:**
+
+``` bash
+sudo mkfs.btrfs /dev/sdXn
+```
+
+**To mount a Btrfs filesystem:**
+
+``` bash
+sudo mount -o options -t btrfs /dev/sdXn /mnt/point
+```
+
+Options can include:
+
+- "compress=zstd" for compression (also supported: lzo, zlis)
+- "noatime" to disable access time updates
+- "subvol=subvolume_name" to mount a specific subvolume
+- "space_cache=v2" for improved space cache management
+- "autodefrag" to enable automatic defragmentation
+
+**Taking a snapshot:**
+
+``` bash
+sudo btrfs subvolume snapshot -r /mnt/point/subvolume /mnt/point/snapshot_name
+```
+
+**Sending a snapshot to another location:**
+
+``` bash
+sudo btrfs send /mnt/point/snapshot_name | sudo btrfs receive /mnt/dest/point
+```
+
+**Sending an incremental snapshot:**
+
+``` bash
+sudo btrfs send -p /mnt/point/snapshot_previous /mnt/point/snapshot_new | sudo btrfs receive /mnt/dest/point
+```
+
+**Delete a snapshot:**
+
+``` bash
+sudo btrfs subvolume delete /mnt/point/snapshot_name
+```

docs/backup/backup-notes.md

@@ -66,6 +66,17 @@ Owner only read and write
 umask 177
 ```
 
+### Find
+
+Find is a very useful command to search files and
+ execute commands on them.
+
+**Find all `.log` files and delete them**
+
+```sh
+find /path/to/search -type f -name "*.log" -exec rm -f {} \;
+```
+
 ## VIM notes
 
 You can use regex expressions on vim, for example,
@@ -94,37 +105,3 @@ You can also snigger by typing `:Sex` to invoke a horizontal split.
 4. Press d to cut (or y to copy).
 5. Move to where you would like to paste.
 6. Press P to paste before the cursor, or p to paste after.
-
-## GPG notes
-
-To export secret key for backup
-
-```sh
-gpg -o private-backup.gpg --export-options backup --export-secret-keys username@example.com
-```
-
-And to import the backup key
-
-```sh
-gpg --import-options restore --import private.gpg
-
-gpg --edit-key username@example.com
-
-> trust
-> 5 (ultimately)
-> save
-```
-
-## SSH notes
-
-Generate safe ssh key pair
-
-```sh
-ssh-keygen -o -a 100 -t ed25519 -f ~/.ssh/id_ed25519 -C "user@email.com"
-```
-
-Add a password to an existing key
-
-```sh
-ssh-keygen -p -f keyfile
-```