Why Does Automatic Let’s Encrypt Renewal Fail?
Fix the SSL extension failure by checking the timer, renewal config, DNS, HTTP/DNS challenge, firewall, credential, rate limit and reload service step by step.
BIPIDA / IDEAS INTO PRACTICE
Bipida blog
Read deeper. Diagnose better. Build with confidence.
Technical analysis and practical experience for your next challenge.
WORDPRESS
LINUX / DEVOPSLooking for a term or account guide?Visit the knowledge base
LINUX / DEVOPSLooking for a term or account guide?Visit the knowledge base
Search and filter articles
Linux
31 articles · Tag: LinuxShowing 13–24
How to Install a Free Let’s Encrypt SSL Certificate
To install the free SSL Let's Encrypt, set up DNS, ACME, Certbot, Nginx, chain of certificates, redirect and automatic renewal step by step and reversible.
How to Configure a Linux Server Firewall Safely
Set up Linux firewall with inventory flow, default policy, secure SSH, IPv4/IPv6, cloud firewall and external testing; with anti-lock rollback.
What Is Fail2ban and Do You Need It?
Fail2ban temporarily blocks logs for failure patterns and IPs; identify restrictions, jail, backend, firewall, test and prevent lockdown.
How to Secure SSH Without Locking Out the Administrator
Secure SSH with separate account, public key, root and password restrictions, firewall, MFA, log and recovery path; without locking administrator access.
How to Apply Basic Linux Server Security Without Locking Yourself Out
Secure the Linux server with inventory, patch, SSH key, separate user, firewall, minimum access, secret, backup and step monitoring; with rollback path.
How to Tune PHP-FPM for a Server
Configure PHP-FPM by measuring worker memory, concurrency, queue, slow log and CPU/RAM capacity and execute the changes stepwise and reversible.
What Is the Linux OOM Killer and Why Does It Stop Services?
Identify the OOM Killer from the kernel log, cgroup, and RAM process, separate the victim process from the stress factor, and fundamentally modify capacity, limit, and…
Why Is the Server Disk Full? Logs, Deleted Files, Docker, and Inodes
Recognize Linux Disk overflow with filesystem, inode, directory, log, deleted file open, Docker and database; without rushing to delete production data.
How to Find the Cause of High Server Memory Usage
Analyze Linux RAM usage with available, cache, swap, RSS/PSS, process, container and OOM and separate the memory leak from normal memory usage.
How to Find the Cause of High Server CPU Usage
To find the cause of the CPU overloading Linux, check the load, user/system/iowait/steal, process, thread, container, PHP and Query in the event timeline.
Why Does a Website Suddenly Go Down on a Server?
When the site goes down, check DNS, network, TLS, Nginx, application and database layer by layer, save evidence, and recover the service with the least risk.