Fonte: https://zerotoroot.me/create-bootable-debian-usb-drive-macos/

There are some things, which are more difficult than they initially seem. This is true for creating a bootable USB drive on Mac with a Linux distro on it.

In this article, we will go through each step necessary to come out with a bootable Linux USB drive.

Let’s begin!

1. Download Debian and Verify the Source

Download the Debian ISO (or any other Linux distro) as well as the signature and checksum files.

Since we are trying to become more security-aware, it’s important to verify the checksum and signature of the Debian image, before continuing.

GPG does just that for us.

$ gpg --verify SHA256SUMS.sign SHA256SUMS
gpg: Signature made Sun May  7 20:28:23 2017 CEST using RSA key ID 6294BE9B
gpg: Good signature from "Debian CD signing key <debian-cd@lists.debian.org>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: DF9B 9C49 EAA9 2984 3258  9D76 DA87 E80D 6294 BE9B

If you get the same “Good signature”, you should be on the safe side.

Converting the Debian ISO to an IMG File

In order for the copying to work, we first need to convert the ISO to an IMG file. This can be done using the hdiutil command.

$ hdiutil convert -format UDRW -o /path/to/output-file.img /path/to/input.iso

I had the file in the folder I was in, thus, I inputted:

$ hdiutil convert -format UDRW -o ./debian-8.8.0-amd64-DVD.img debian-8.8.0-amd64-DVD-1.iso
Reading Driver Descriptor Map (DDM : 0)…
Reading Debian 8.8.0 amd64 1             (Apple_ISO : 1)…
Reading Apple (Apple_partition_map : 2)…
Reading Debian 8.8.0 amd64 1             (Apple_ISO : 3)…
Reading EFI (Apple_HFS : 4)…
Reading Debian 8.8.0 amd64 1             (Apple_ISO : 5)…

.......................................................................................
Elapsed Time: 15.632s
Speed: 243.7Mbytes/sec
Savings: 0.0%
created: ~/Downloads/debian-8.8.0-amd64-DVD.img.dmg

The resulting file, might also have .dmg appended to it, as is the case above.

One more step is missing before we can write the file to the USB drive. We first need to unmount the USB drive.

Run diskutil list to see what disk the correct one is. If you are unsure, run the command twice. Once without USB drive plugged in, once with.

$ diskutil list
/dev/disk0 (internal, physical):
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:      GUID_partition_scheme                        *251.0 GB   disk0
  1:                        EFI EFI                     209.7 MB   disk0s1
  2:                  Apple_HFS Macintosh HD            210.8 GB   disk0s2
  3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1 (external, physical):
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:      GUID_partition_scheme                        *30.8 GB    disk1
  1:                        EFI EFI                     209.7 MB   disk1s1
  2:                  Apple_HFS Debian Boot             30.4 GB    disk1s2

In this case, it’s /dev/disk1. Then unmount it.

$ diskutil unmountDisk /dev/disk1
Unmount of all volumes on disk1 was successful

Write the Operating System to the USB Drive

Now this is the step, where you really need to pay attention. Writing to the wrong disk could cause your operating system to be overwritten. Thus, backup before and double check that the output file is the correct disk.

$ sudo dd if=/path/to/inputfile.img of=/dev/rDISK bs=1m

An r is placed before the disk-identifier, because using it during writing will speed up the process. Everything else is the same as above.

$ sudo dd if=debian-8.8.0-amd64-DVD.img.dmg of=/dev/rdisk1 bs=1m

It will take a bit, till it’s finished. Once it is, two things will happen:

1. You will see a popup such as this:
   
   Ignore it for now.
2. In the console you will see an output similar to this:3809+1 records in
   3809+1 records out
   3994091520 bytes transferred in 74.693837 secs (53472839 bytes/sec)

Meaning the program has finished writing. First, eject the USB drive.

$ diskutil eject /dev/disk1
Disk /dev/disk1 ejected

Then choose ignore on the dialog box option.

You are now all set. Plug in the USB drive the next time you want to boot from it or install the operating system.

ow do I access my enterprise NAS server by mounting NFS filesystem onto my Mac OS X based system using GUI and command line based tools?

Network File System (NFS), a distributed file system protocol developed by Sun Microsystems. NFS is the common for file sharing on NAS server and Linux / UNIX systems like, HP-UX, Solaris, Mac OS X, and

others. Mac OS X can be setup as an NFS client to access shared files on the network. Mounting NFS volumes in OS X can be done using following methods:

a] Command line option.

b] GUI option.

macOS X Mount NFS Share / Set an NFS Client

Our sample setup for macOS client and nfs server:

        nas01                                   Laptop/Desktop
   +--------------+                           +--------+
   |  UNIX/Linux  |                           | Mac    |
   |    NFS       +---------------------------+ OS X   |
   |   SERVER     |  mount nas01:/mp3 /nfs    | Client |
   +--------------+                           +--------+
         |                                    (192.168.3.100)
     (shared dirs)
         /
         --/Sales
         --/Mp3
         --/Data
         --/wwwroot
   (192.168.3.1) 

nas01 allows your users or client compute to access files over a network. Mac OS can mount file system over a network and work as they are mounted locally. This is perfect for sharing files or centralized home directories. See how to setup an NFS server under RHEL / CentOS Linux and Ubuntu Linux here.

How Do I Find Out Shared Directories?

To mount an NFS file system, the resource must be made available on the NAS or NFS server. To verify that resource available open the terminal and type the following command:
$ showmount -e nas01
$ showmount -e nfs-server-ip-address-here
$ showmount -e nas01.lan.nixcraft.net.in
Sample outputs:

The showmount command show remote NFS mounts (resources).

Mac OS X Nfs mount Command

First, create a directory to mount an nfs share, enter:
$ sudo mkdir /private/nfs
$ sudo mkdir /private/mp3
To mount an NFS file system, enter:
$ sudo mount -t nfs nas01:/mp3 /private/nfs
OR
$ sudo mount -t nfs 192.168.3.1:/mp3 /private/nfs
To mount an NFS file system in read/write mode, enter:
$ sudo mount -o rw -t nfs nas01:/mp3 /private/nfs

Tip: Operation not permitted Error

If you get an error which read as follows:

 192.168.3.1:/mp3 Operation not permitted

Try to mount it as follows with -o resvport command:
$ sudo mount -t nfs -o resvport 192.168.3.1:/mp3 /private/nfs
OR mount an NFS in read/write mode, enter:
$ sudo mount -t nfs -o resvport,rw 192.168.3.1:/mp3 /private/nfs
From the man page:

resvport
Use a reserved socket port number. This is useful for mounting
servers that require clients to use a reserved port number on the
mistaken belief that this makes NFS more secure. (For the rare
case where the client has a trusted root account but untrustwor-
thy users and the network cables are in secure areas this does
help, but for normal desktop clients this does not apply.)

Verify: NFS Is Working or Not

Type the following commands:
$ df -H
$ cd /private/nfs
$ ls -l
Sample outputs (note I’ve mounted it at /private/mp3/ dir):

How Do I Copy Files?

Use the cp command:
$ cp /path/to/file.doc /private/nfs/
$ cp -a /path/to/*pl /private/nfs/
$ cp /private/nfs/mp3/*.mp3 ~/mp3

Using the Finder

Note: The following entry “NFS mounts” in the Disk Utility does NOT exist in MAC OS X v10.8+. The following discussion only applies to the older Mac OS X version <= 10.7.x and eariler.

The Finder is the default file manager used on the Mac OS and Mac OS X operating systems that is responsible for the overall user-management of files, disks, network volumes and the launching of other applications. Open Finder > Shared (select from the left sidebar) > NFS server (nas01 or 192.168.3.1):

Now, you can copy and paste files as usual.

Recommend mount Command Options

I suggest that you run the mount command it as follows to get better a performance:
$ sudo mount -t nfs -o soft,intr,rsize=8192,wsize=8192,timeo=900,retrans=3,proto=tcp nas01:/sales /private/sales
OR
$ sudo mount -t nfs nfs -o soft,timeo=900,retrans=3,vers=3, proto=tcp nas01:/sales /private/sales
See mont_nfs(8) for more information.

GUI Method: HowTo Set Mac OS X As an NFS Client

To mount an NFS share from OS X using GUI tools, follow these steps:

[1] Start Finder, and go to Applications / Utilities / Disk Utility:

You will see the disk utility as follows:

[2] Alternatively, you can select “Disk utility” > click on File > Mount NFS as follows:
You will see an “NFS mounts” window as follows:

[3] Click on “+” icon:

You need to enter your remote NFS server URL (IP address or dns name) in the following format:
nfs://192.168.3.1/mp3
nfs://nas01/mp3
Where,

1. 192.168.3.1: NFS server IP address.
2. nas01: NFS server dns name.
3. mp3: Shared nfs directory name.

You need to set mount location as follows:
/Volumes/mp3
/Volumes/mp3 is nothing but the mount location. This is a convenient place. In this example, you entered the URL as nfs://192.168.3.1/mp3, enter /Volumes/mp3 as the mount location. Please note that don’t create the subdirectory (mp3); it will be created dynamically when the share is mounted.

Optional

Click the arrow in front of “Advanced Mount Parameters”. A new text entry box is displayed. Enter: resvport (this is only required if you get some sort of error [see above for more info or read mount_nfs man page]).
[4] Finally, click “Verify” button at the bottom right:

[5] You will see a popup window, stating that “The NFS server appears to be functional” > Click “OK” button to continue. Finally, Click “Save” button. You may be prompted for the password to make changes. Your NFS share should appear at the mount location you entered above i.e. /Volumes/mp3.

You can access /Volumes/mp3 using the Finder:

You can also use command line options:
$ ls /Volumes/mp3
$ cd /Volumes/mp3
$ cp /path/to/something.file.in file.out
$ rsync -av user@server3.nixcraft.com:/var/www/html/ server.backups/

Fonte: https://www.cyberciti.biz/faq/apple-mac-osx-nfs-mount-command-tutorial/

How to setup NFS server on Debian 10[NFS share mount]

Fonte: https://markontech.com/linux/setup-nfs-server-on-debian/

Overview

In this post, we’ll walk you through a process how to setup NFS server on Debian 10 and the process is same for Debian 11. Earlier on this site, we covered the other method as well where we showed the process mounting the network shared drive on Linux, but with this method we used cifs-utils tools(LINK). The principle behind this process is basically the same – mount a network shared folder or drive from another machine and access it via local network.

NFS server and client

NFS tools consists of the server application and client application. The server application, of course you install on the machine of which folder or drive you want to share over the network. The client application you install on all other machines from which you use to access the network shared folder/drive on the server.

One small note:

For this to work, your server machine needs to have  a static IP address.

Setup NFS server

NFS server installation

On you server machine, run this command to install NFS:

sudo apt install nfs-kernel-server

Next step – NFS server configuration. Run this command to access the NFS server config:

sudo nano /etc/exports

The configuration syntax needs to look something like this(the configuration line will explained in detail). I  will explain the syntax more in detail bellow:

/home/sharedfolder     192.168.100.0/24(rw,sync,no_subtree_check)

Save the file and exit. Then run the command:

sudo exportfs -ra

And restart the NFS server:

sudo systemctl restart nfs-kernel-server.service

And that’s the NFS server configuration part. The file needs to look something like this:

Note for the shared folder

Also, for the folder you shared… if the folder was created by a root user, or with a user with the sudo privileges and from the client machine, you’re using an account which is not root – there could be read and write issues when accessing the folder from the client.

In that case, you should change the directory permissions and ownership of the server’s shared folder like this:

sudo chown -R nobody:nogroup /home/sharedfolder/
sudo chmod -R 755 /home/sharedfolder/

This means that the shared folder is not owned by any account or local group and has read and write permissions.

Another thing

If you’re running a  ufw firewall on your server, then also we need to add a firewall rule in order that from the client machine we can access the shared folder. Run this command for the ufw firewall:

sudo ufw allow from 192.168.100.0 to any port nfs

The IP address needs to be of your IP pool.

NFS server configuration syntax

Ok, let’s cover the NFS server configuration. So, in previous paragraph I used this command as an example:

/home/sharedfolder 192.168.100.0/24(rw,sync,no_subtree_check)

This configuration syntax is for a scenario where you want for your NFS shared folder to be available on entire local network for anyone under 192.168.100.0 IP pool.

We’ll cover this syntax in detail:

• /home/sharedfolder – this is of course, the directory path of the folder you want to share over the network. This also can be any directory on the system(replace sharedfolder with the actual folder name)
• 192.168.100.0/24 – the IP address of clients/network pool and subnet mask. Above I already mentioned one case with the IP address where you want for the NFS shared folder to be accessed by any client on entire local network. In this case you need to know the IP pool of your router. This also can be configured so that only specific clients can access the NFS network share. For this to work, clients also needs to have a static IP address which you can assign by yourself. In this case a syntax would look like something like this:
  • /home/sharedfolder 192.168.100.14(rw,sync,no_subtree_check)
  • And if you need to have a scenario for multiple specific clients to access the NFS share, then you need to add multiple lines for each client individualy… like this:
  • /home/sharedfolder 192.168.100.14(rw,sync,no_subtree_check)
  • /home/sharedfolder 192.168.100.38(rw,sync,no_subtree_check)
• (rw,sync,no_subtree_check) – in this part, in between these brackets we are adding the share properties like client permissions and etc…
  • rw -This option gives the client machine both read and write access to the shared folder.
  • sync – This option forces NFS to write changes to disk before replying. This results in a more stable and consistent environment since the reply reflects the actual state of the remote volume. However, it also reduces the speed of file operations.
    
  • no_subtree_check – This option prevents subtree checking, which is a process where the server must check whether the file is actually still available in the exported tree for every request. This can cause many problems when a file is renamed while the client has it opened. In almost all cases, it is better to disable subtree checking.

NFS client installation and mounting the NFS network share

On the client machine, run these commands to install the NFS client:

sudo apt update
sudo apt install nfs-common

Next step is to create a mount point on the client machine. Command bellow is used as an example. This can also be any location:

sudo mkdir /mnt/nfs-share

Now we can mount our NFS network share folder:

sudo mount 192.168.100.119:/home/sharedfolder/ /mnt/nfs-share

Again, the IP in the above command needs to be of your server and this command should mount the network share on your client machine. The shared folder should appear in the file manager right away… Like this(Example picture bellow):

Testing the NFS network share with the terminal

You can, of course, test the network share using the file manager and through the desktop environment . But, I also like to test the share via terminal. The method testing with the terminal is also good for scenario where you don’t have a monitor and accessing a remote server.

sudo touch /mnt/nfs-share/test.txt

This command will create a .txt file on our mount point and that file should appear right away on our server. Like in the pictures bellow:

Mounting the network share on boot

The mount command we used earlier – basically, that was a manual mount and it’s not permanent. Meaning that, as soon as you restart or turn off your client machine… the mount will be gone and you need to manually mount it again.

However, there’s a way to mount it permanently and that is with the configuration to mount the network share on boot. So, when your client machine boots up, it will automatically mount the network share.

This method is optional and you do it if you want to.

!!!PLEASE PAY ATTENTION ON THIS STEP!!!

If you don’t do it properly, you could lock up your machine on the next restart. Fstab file is the boot process configuration file which has your HDD’s in it as well. So, if the file is not configured properly, you could prevent the machine from booting.

On client machine, run this command to access the fstab file:

sudo nano /etc/fstab

Then… AT THE END OF THE FILE add this command line:

192.168.100.119:/home/sharedfolder   /mnt/nfs-share   nfs   rw,soft,noatime,x-gvfs-show

It should look like this:

Save the file and exit. And that is it. The first two parts of the command tells the client to access the server and to mount the network shared folder on the client’s mount point. For this mount method, we used quite few mount options and properties and that is in order to make the mount stable as much as possible and avoid any read write issues. You can check the explanation of the option in the man page of the NFS on terminal:

man nfs

or on the web versions of the NFS man page – manpage1 and manpage2

Summary

That was the process how to setup NFS server on Debian 10 and on Debian 11. Here, not only we covered the installation process and the configuration for the client and server machine – but, also covered the mounting process and how to access the NFS share and some potential risks as well.

Thank you very much for your time.

Fonte: https://www.tecmint.com/install-debian-11-minimal-server/

In this guide, we will walk you through the installation of a Debian 11 (Bullseye) Minimal Server, using the netinstall CD ISO image. This installation you will carry out is appropriate for building a future customizable server platform, without a GUI (Graphical User Interface).

[ You might also like: A Fresh Installation of Debian 11 Bullseye Desktop ]

You can use it to install only the necessary software packages that you need to work with, which we will show you in future guides. However, before you move further, read the system requirements, download the netinstall CD ISO image and then proceed to the Debian 11 installation instructions.

Requirements

• Minimum RAM: 512MB.
• Recommended RAM: 2GB.
• Hard Drive Space: 10 GB.
• Minimum 1GHz Pentium processor.

Important: These are only values for a test scenario, in a production environment, you probably want to use suitable RAM and Hard disk size to meet your local environment needs.

Download Debian 11

Debian 11 server system network installation minimal CD image:

• For 32-bit: Debian-11.1.0-i386-netinst.iso
• For 64-bit: Debian-11.1.0-amd64-netinst.iso

Installation of Debian 11 Minimal Server

1. After downloading the Debian 11 minimal CD image from the above links, burn it to a CD or create a bootable USB stick using LiveUSB Creator called Unetbootin or Rufus.

2. Once you have created the installer bootable media, place your CD/USB into your system appropriate drive.

Then start the computer, select your bootable device, and the first Debian 9 installer boot menu should appear as shown below. Choose Install and press the [Enter] key.

3. The system will start loading the media installer and a page to select the installation language should appear as shown below. Select your installation process language and click on Continue.

Configuring Location and Keyboard Settings

4. Now select your location used for setting the system timezone and locales, if not on the list go to Other and click on Continue. Find the region and the country. Once you are done click Continue as shown below.

5. Next, choose your Keyboard Layout to use and click Continue.

6. The installer will now load components from the CD shown below.

Configure Hostname and Domain Name

7. The next step is to set your system hostname and domain name and click Continue.

Configure Users and Password

8. Here, you will configure system users and their passwords. Start by setting the root user password as shown below and click Continue when you are done.

9. Then create a user account for the system administrator. First set the user’s full name as shown below and click Continue when you are done.

10. In this step, set the user’s system name and click Continue.

11. Now set the above user’s password and click Continue.

12. Configure your system clock.

Partitioning Disk

13. On the next screen, choose Manuel to perform disk partitioning.

Note: You can select Guided – use the entire disk and set up LVM (Logical Volume Manager) as partition layout for efficient disk space management and follow the instructions.

14. You will see an overview of your current system disks and mount points. Select the disk to be partitioned and click Continue.

After that, select Yes to create a new empty partition table on the disk.

15. Next, select the free space on the disk to partition it and click Continue.

Creating Swap Partition

16. Now create the Swap area by selecting Create a new partition and set appropriate size as shown in the screenshots below. Then click Continue.

17. Set swap partition as Primary and choose the Beginning of the free space on disk and click Continue.

18. Now set partition as Swap area as shown in the following screenshot.

19. Now select Done setting up the partition and click Continue.

Create Root Partition

20. In this step, you can now create the root partition by selecting the free space, then select Create a new partition. Afterward set the root partition size, make it Primary and set it at the beginning of the free space.

Then use the Ext4 file system on it and finally select Done setting up partition and click Continue as shown in the following screenshots.

Create Home Partition

21. Similarly to create a /home partition follow the same instruction as explained above using the remaining free space if you have.

22. Once you have created all the necessary partitions, click on Finish partitioning and write changes to disk.

Finalizing Debian 11 Installation Process

23. At this point, installation of the base system should begin as shown below.

24. Now configure the package manager as shown in the screenshot below. Select No and click Continue.

25. Afterwards, configure a network mirror by selecting the nearest country and then click Continue.

26. Next, choose whether to participate in the package usage survey or not. Then click Continue.

27. Now install standard system utilities and click Continue.

28. In this step, you will install the Grub boot loader by choosing Yes. After which you should choose the disk to install it.

29. Finally, the installation is done, click Continue to reboot the machine and remove the bootable media, then boot in your system and login.

That’s all. You now have a working Debian 11 (Bullseye) Minimal Server for developing a future customizable server platform. If you are looking to deploy a web server such as Apache or Nginx, go through the following articles.

• Install LAMP (Linux, Apache, MariaDB or MySQL and PHP) Stack on Debian
• How to Install LEMP (Linux, Nginx, MariaDB, PHP-FPM) on Debian
• The Ultimate Guide to Secure, Harden, and Improve Performance of Nginx Web Server

To send us any queries or thoughts, use the comment section below.

Fonte: https://www.tecmint.com/install-lamp-in-debian/

On (August 14, 2021), the Debian project announced the availability of the new stable version (Debian 11) codenamed Bullseye.

With this release, the well-known and widely-used Debian 10 Buster gained old-stable status, which designates the previous stable repository. As it always happens with the release of a new stable version, Bullseye includes hundreds of new packages and updates to thousands of others.

Since Debian powers a large percentage of web servers all over the world, in this article we will explain how to install the LAMP stack in Debian 11 and also works on older Debian 10 and Debian 9 releases.

This will allow system administrators to set up brand new web servers on top of Bullseye using the recent updates to the distribution’s official repositories. It is assumed that you have installed Debian 11 minimal server on a bare metal, virtual machine, or VPS, or have upgraded from Debian 10 to Debian 11.

Installing LAMP in Debian

The “M” in LAMP stands for MariaDB or MySQL, the database server for the stack. Depending on your choice, you can install the database server and the other components (the Apache web server and PHP) as follows.

Install LAMP with MariaDB on Debian

# apt update && apt install apache2 mariadb-server mariadb-client mariadb-common php php-mysqli

Install LAMP with MySQL on Debian

# apt update && apt install apache2 mysql-server mysql-client mysql-common php php-mysqli

As a personal preference, I will use MariaDB in the rest of this article.

Once the installation is complete, let us make sure all the services are running. If so, the following commands.

# systemctl is-active apache2
# systemctl is-active mariadb

should return active for both. Otherwise, start both services manually:

# systemctl start {apache2,mariadb}

Securing MariaDB in Debian

Finally, before proceeding let’s use mysql_secure_installation to set up the password for the database root account, remove anonymous users, disallow root login remotely and remove test database.

# mysql_secure_installation

Testing LAMP on Debian

To begin, we are going to create and populate a sample database. Next, we will use a basic PHP script to retrieve a set of records from the database in JSON format.

Finally, we will use Firefox’s developer tools to verify the version of Apache being used. Although we could find out this same information with.

# apache2 -v

Server version: Apache/2.4.51 (Debian)
Server built:   2021-10-07T17:49:44

the reason why we’re using a script is to make sure all the components of the stack are working properly when bundled together.

Creating and Populating a Database

Let’s enter the MariaDB prompt with the following command.

# mysql -u root -p

and enter the password that was chosen in the previous section.

Now we will create a database named LibraryDB as follows:

MariaDB [(none)]> CREATE DATABASE LibraryDB;

and add two tables named AuthorsTBL and BooksTBL:

MariaDB [(none)]> USE LibraryDB;
CREATE TABLE AuthorsTBL (
AuthorID INT NOT NULL AUTO_INCREMENT,
FullName VARCHAR(100) NOT NULL,
PRIMARY KEY(AuthorID)
);

MariaDB [(none)]> CREATE TABLE BooksTBL (
BookID INT NOT NULL AUTO_INCREMENT,
AuthorID INT NOT NULL,
ISBN VARCHAR(100) NOT NULL,
Title VARCHAR(100) NOT NULL,
Year VARCHAR(4),
PRIMARY KEY(BookID),
FOREIGN KEY(AuthorID) REFERENCES AuthorsTBL(AuthorID)
);

For security reasons, we will create a special account to access our database:

MariaDB [(none)]> CREATE USER 'librarian'@'localhost' IDENTIFIED BY 'Today123';
MariaDB [(none)]> GRANT ALL PRIVILEGES ON LibraryDB.* TO 'librarian'@'localhost';

The last step now consists of populating the tables with Authors and Books:

MariaDB [(none)]> INSERT INTO AuthorsTBL (FullName) VALUES ('Paulo Coelho'), ('Isabel Allende'), ('Jorge Luis Borges');
MariaDB [(none)]> INSERT INTO BooksTBL (AuthorID, ISBN, Title, Year) VALUES
(1, '9788576653721', 'El alquimista', '1988'),
(1, '9780061194740', 'El peregrino', '1987'),
(2, '9789500720380', 'La casa de los espiritus', '1982'),
(3, '9789875666481', 'El Aleph', '1945');

Testing Database Connection with PHP Script

The following PHP script will first connect to the database and retrieve the records that match the query. If an error occurs, a descriptive message will be displayed so as to give us a hint on what’s wrong.

Save the following script as booksandauthors.php under /var/www/html:

<?php
	// Show PHP version
	echo "Current PHP version: " . phpversion() .  "\r\n";

	// Connect to database
	$connection = mysqli_connect("localhost","librarian","Today123","LibraryDB") or die("Error " . mysqli_error($connection));

	// SQL query
	$sql = "SELECT A.ISBN, A.Title,
        	A.Year, B.FullName
        	FROM BooksTBL A JOIN AuthorsTBL B
        	ON A.AuthorID = B.AuthorID;";
	$result = mysqli_query($connection, $sql) or die("Error " . mysqli_error($connection));

	// Populate an array with the query results
	$libraryarray = array();
	while($row = mysqli_fetch_assoc($result))
	{
    	$libraryarray[] = $row;
	}

	// Convert to JSON
	echo json_encode($libraryarray);
?>

Change the ownership to www-data and add the appropriate permissions:

# chown www-data:www-data /var/www/html/booksandauthors.php
# chmod 600 /var/www/html/booksandauthors.php

Finally, open a web browser and point it to the URL where the script resides.

http://192.168.0.35/booksandauthors.php

That’s it! In this article, we have explained how to install and test the LAMP stack on Debian 11. If you have questions or comments about this article, don’t hesitate to let us know by using the form below.

If you use a local development environment, you may run into problems that are similar to those on a live server. In some cases, your WordPress website may be unable to connect with its database because MySQL isn’t running or it shut down unexpectedly.

Depending on which local environment you use, the process of troubleshooting your MySQL database might vary a bit. With XAMPP, the process is remarkably straightforward since you get access to a control panel instead of having to rely on the command line only.

In this article, we’ll explain what XAMPP is and what the “MySQL shutdown unexpectedly” error means. Then we’ll walk you through three methods you can use to fix it. Let’s get to it!