Miscellaneous SysAdmin Guide

Formatting External Hard Drive
Mounting External Hard Drive
- Enabling External Hard Drive Mount Upon Reboot
Mounting a SMB Share in Ubuntu
Setting Up Samba
SSH Keys

Formatting External Hard Drive

I recommend formatting with the ext4 file system as it is most common on modern Linux systems.

Display all block devices with file system information (the partitions that do not contain information on the file system in use are non-formatted partitions)
```
 lsblk -f
```
Format a disk partition with ext4 file system
```
 sudo mkfs -t ext4 /path/to/device
```
Verify the file system change
```
 lsblk -f
```

Mounting External Hard Drive

Plug in hard drive
List all block devices with the name, size, file system type, mount location, and Universally Unique Identifier (take note of the UUID as it will be needed later on)
```
 sudo lsblk -o NAME,SIZE,FSTYPE,TYPE,MOUNTPOINT,UUID
```
Take note of the name of desired hard drive name will be listed on far left side
Locate the mount location of the external drive
```
 sudo mount [NAME] [MOUNT LOCATION]
```
Check to make sure hard drive is mounted
```
 df -h
```

Enabling External Hard Drive Mount Upon Reboot

Edit filesystem table
```
 sudo nano -Bw /etc/fstab
```

Below last PARTUUID entry

 UUID=[INSERT UUID] /mnt/USB auto defaults,user,nofail 0 2

Press ^X to exit, Y to save changes, and Enter to confirm
Make sure that hard drive will mount upon startup
```
 sudo reboot
```

This can either be done remotely via SSH from your local machine or directly on the server itself.

Update packages

 sudo apt-get update && sudo apt-get upgrade -y

Install CIFS Utilities
```
 sudo apt-get install cifs-utils -y
```
Create directories where you want network shares to mount (ex: /media/nas)
```
 mkdir media/nas
```
In home folder (/home/user) create a new text file inside a directory called smb that will contain the username and password of the network share
```
 nano smb/.smbcredentials
```

Inside text file -

 username=[username-of-server]
 password=[password-of-server]

Edit filesystem table
```
 sudo nano -Bw /etc/fstab
```

Append the following at the bottom of the file

 //SERVER-IP/name-of-share /path-to-mount-location cifs credentials=/path/to/credentials/.smbcredentials,vers=3.0,uid=1000,gid=1000 0 0

Mount SMB share type
```
 sudo mount -a
```

Setting Up Samba

A Samba file server enables file sharing across different operating systems over a network.

Samba Installation

Install the required Samba files

sudo apt-get install samba samba-common-bin

Edit smb configuration file
```
 sudo nano /etc/samba/smb.conf
```

At the bottom of the file

 [INSERT LABEL OF HARD DRIVE]
 comment = LABEL OF HARD DRIVE
 public = no
 writeable = yes
 browsable = yes
 path = /path-to-mount-point
 create mask = 0777
 directory mask = 0777
 only guest = no

Require a login for server connection
```
 sudo smbpasswd -a $USER
```

Have Finder.app active and press Command + K
Type smb://[INSERT IP]
Click Connect
Type in pi as username and your previously chosen password
Click on hard drive label to mount the server

SSH Keys

SSH Keys are stronger than plain text passwords since authentication requires both a private and public key pair.

Creating a SSH Key on Mac

To generate a SSH Key - ssh-keygen -t ed25519
The prompt will ask where you want to store the RSA private and public keys. If you press Enter then both keys will be stored in the .ssh hidden directory.
The next prompt will ask if you want to enter a passphrase. I recommend doing this since leaving this blank will allow anyone who gains control of your private key to login to your servers.
```
 ~/.ssh/id_rsa - this is your private key (DO NOT SHARE THIS)
 ~/.ssh/id_rsa.pub - this is your public key which you will be copying over to your server
```

Configure SSH To Always Use Keychain

ssh-add --apple-use-keychain ~/.ssh/[your-private-key]

Adding the New SSH Key, so That It Can Get Picked Up for Every Terminal Session Automatically

Create a config file in .ssh folder - touch config

Type the following inside the config file

 Host [ip-address / URL]
   AddKeysToAgent yes
   UseKeychain yes
   IdentityFile ~/.ssh/[your-private-key]

Copying Public Key to Server

 ssh-copy-id -i ~/.ssh/[your-public-key] user@host

Table of Contents