#Devops

[nixcraft]

the audacity. lol.

[kernelbroken]

[heart-ghost-studyblr]

At my last sip of that licor, tasting like honey yet often mistaken for whiskey (we’re talking about the old Jackie), I found myself surrounded by companions daring to tackle a real software architecture challenge. We shared a good wine and cheese to conquer it together! (Unfortunately, there’s always something waiting to be dealt with on Monday.)

The glow of my Neovim terminal in Monokai theme reflects my rhythm — a guy who doesn’t stop on weekends but knows that balance isn’t about being all-in, all day.

The setup screams character: a seamless fusion of productivity and comfort. Lazygit commands at my fingertips, a Ghibli-esque avatar paired with Neofetch adding a touch of Tumblr aesthetic, and a playlist of Korean indie OSTs playing in the background to add depth to every keystroke.

This is how I drive — in code, creativity, and moments that are unapologetically mine.

[izder456]

How do I Learn Linux or *BSD for DevOps, Sysadmin, or Programming?

The "cold turkey hacker method".

Daily drive one. Make it your main system. Use as many native tools from that distro or BSD system as possible.

Don’t copy-paste shit blindly. Read, understand, then type.

No dual booting or virtualization. VMs and dual booting give you an easy reset. They encourage reinstalling over fixing issues. You’ll never learn that way.

No compatibility layers (e.g., Wine, Linuxulator on FreeBSD, Waydroid). If you’re using non-native tech, you’re defeating the purpose of this guide.

Make this your only system. Your only personal computing device should be the OS you're learning.

How to Learn:

Learn by trial.

Learn by error.

Learn by doing.

Learn by creating.

Learn by experimentation.

Learn by failure.

Learn by exposure.

Stop:

Stop reading guides.

Stop following "must-do’s" from others.

These rarely help you learn the intricacies of your system.

There is no "right way" to learn this. Just long, hard, grueling, labor.

Where to Start:

Learn the basics first. The manpages, the wiki, the handbook, the FAQ. Official documentation is your first stop.

Build knowledge from there. Use what you learn to make solutions following the standard practices of your system.

Actively work on your system. Constantly push it to do what you want it to do.

TL;DR:

Make your system do what you want. To do that, you need to understand its capabilities first. Start there.

[linuxtldr]

Can't bots just trust we're human without the robot dance-off? 😄

[antifataylorswift]

The developers i work with are asking chatgpt questions about my infrastructure that are in our docs. Unsurprisingly they are getting bad advice for our particular setup, and are bothering my team with a bunch of questions about if the advice is right and what would happen if they ran those commands.

[acmemindspvt]

Role of Data Engineering Solutions in Modern Business

AcmeMinds, a leading data engineering company, provides comprehensive data engineering services to help businesses transform raw data into actionable insights. Their tailored data engineering solutions include building scalable data pipelines, data cleaning and transformation, real-time analytics, and support for AI and machine learning. AcmeMinds empowers businesses to optimize decision-making, enhance operational efficiency, and drive sustainable growth.

[daveio]

Hire me!

A reminder that I'm looking for work.

I'm a high-level devops engineer with experience of running my own team. I've previously worked at Facebook and Mozilla.

My CV is available at https://dave.io/go/cv if you want to check it out.

Feel free to share it with anyone who might be interested.

Thanks!

[nixcraft]

[kernelbroken]

[heart-ghost-studyblr]

Normal night in the midnight.

[atcuality1]

Secure and Scalable Cloud Server Management at Atcuality

For businesses seeking to enhance scalability and maintain top-tier security, Atcuality provides unparalleled cloud server management services. Our solutions cover all aspects of cloud server maintenance, including load balancing, patch management, data backups, and disaster recovery planning. Our experienced professionals work with cutting-edge tools to ensure that your servers are secure, efficient, and scalable to meet changing business needs. Whether you operate in e-commerce, finance, or technology, we tailor our services to align with your operational goals. With Atcuality as your trusted partner, you can focus on driving growth while we handle the technical complexities of cloud management.

[linuxtldr]

Windows: Hungry beast, Linux: Energy sipper!

[qcsdclabs]

Understanding the Boot Process in Linux

                    Six Stages of Linux Boot Process

Press the power button on your system, and after few moments you see the Linux login prompt.

Have you ever wondered what happens behind the scenes from the time you press the power button until the Linux login prompt appears?

The following are the 6 high level stages of a typical Linux boot process.

                             BIOS        Basic Input/Output System

                             MBR        Master Boot Record executes GRUB

                             GRUB      Grand Unified Boot Loader Executes Kernel

                             Kernel      Kernel executes /sbin/init

                             Init            init executes runlevel programs

                             Runlevel   Runlevel programs are executed from /etc/rc.d/rc*.d/

1. BIOS

BIOS stands for Basic Input/Output System

Performs some system integrity checks

Searches, loads, and executes the boot loader program.

It looks for boot loader in floppy, cd-rom, or hard drive. You can press a key (typically F12 of F2, but it depends on your system) during the BIOS startup to change the boot sequence.

Once the boot loader program is detected and loaded into the memory, BIOS gives the control to it.

So, in simple terms BIOS loads and executes the MBR boot loader.

2. MBR

MBR stands for Master Boot Record.

It is located in the 1st sector of the bootable disk. Typically /dev/hda, or /dev/sda

MBR is less than 512 bytes in size. This has three components 1) primary boot loader info in 1st 446 bytes 2) partition table info in next 64 bytes 3) mbr validation check in last 2 bytes.

It contains information about GRUB (or LILO in old systems).

So, in simple terms MBR loads and executes the GRUB boot loader.

3. GRUB

GRUB stands for Grand Unified Bootloader.

If you have multiple kernel images installed on your system, you can choose which one to be executed.

GRUB displays a splash screen, waits for few seconds, if you don’t enter anything, it loads the default kernel image as specified in the grub configuration file.

GRUB has the knowledge of the filesystem (the older Linux loader LILO didn’t understand filesystem).

Grub configuration file is /boot/grub/grub.conf (/etc/grub.conf is a link to this). The following is sample grub.conf of CentOS.

#boot=/dev/sda

default=0

timeout=5

splashimage=(hd0,0)/boot/grub/splash.xpm.gz

hiddenmenu

title CentOS (2.6.18-194.el5PAE)

          root (hd0,0)

          kernel /boot/vmlinuz-2.6.18-194.el5PAE ro root=LABEL=/

          initrd /boot/initrd-2.6.18-194.el5PAE.img

As you notice from the above info, it contains kernel and initrd image.

So, in simple terms GRUB just loads and executes Kernel and initrd images.

4. Kernel

Mounts the root file system as specified in the “root=” in grub.conf

Kernel executes the /sbin/init program

Since init was the 1st program to be executed by Linux Kernel, it has the process id (PID) of 1. Do a ‘ps -ef | grep init’ and check the pid.

initrd stands for Initial RAM Disk.

initrd is used by kernel as temporary root file system until kernel is booted and the real root file system is mounted. It also contains necessary drivers compiled inside, which helps it to access the hard drive partitions, and other hardware.

5. Init

Looks at the /etc/inittab file to decide the Linux run level.

Following are the available run levels

0 – halt

1 – Single user mode

2 – Multiuser, without NFS

3 – Full multiuser mode

4 – unused

5 – X11

6 – reboot

Init identifies the default initlevel from /etc/inittab and uses that to load all appropriate program.

Execute ‘grep initdefault /etc/inittab’ on your system to identify the default run level

If you want to get into trouble, you can set the default run level to 0 or 6. Since you know what 0 and 6 means, probably you might not do that.

Typically you would set the default run level to either 3 or 5.

6. Runlevel programs

When the Linux system is booting up, you might see various services getting started. For example, it might say “starting sendmail …. OK”. Those are the runlevel programs, executed from the run level directory as defined by your run level.

Depending on your default init level setting, the system will execute the programs from one of the following directories.

Run level 0 – /etc/rc.d/rc0.d/

Run level 1 – /etc/rc.d/rc1.d/

Run level 2 – /etc/rc.d/rc2.d/

Run level 3 – /etc/rc.d/rc3.d/

Run level 4 – /etc/rc.d/rc4.d/

Run level 5 – /etc/rc.d/rc5.d/

Run level 6 – /etc/rc.d/rc6.d/

Please note that there are also symbolic links available for these directory under /etc directly. So, /etc/rc0.d is linked to /etc/rc.d/rc0.d.

Under the /etc/rc.d/rc*.d/ directories, you would see programs that start with S and K.

Programs starts with S are used during startup. S for startup.

Programs starts with K are used during shutdown. K for kill.

There are numbers right next to S and K in the program names. Those are the sequence number in which the programs should be started or killed.

For example, S12syslog is to start the syslog deamon, which has the sequence number of 12. S80sendmail is to start the sendmail daemon, which has the sequence number of 80. So, syslog program will be started before sendmail.

There you have it. That is what happens during the Linux boot process.

for more details visit www.qcsdclabs.com