Linux Troubleshooting

When a service cannot start because a port is already in use, the first step is to identify which process is listening on that port. Using ss This lists listening TCP ports and the process information where available. Using lsof Replace 8080 with the port you are checking. Older systems ss is generally preferred on … Read more

Name resolution is the process of turning a hostname into an IP address. When a Linux machine cannot reach a host by name, check DNS settings before assuming the network itself is down. Check resolver configuration This shows the name servers currently being used by the system. On many modern distributions this file may be … Read more

Telnet sends traffic without encryption and should not be used for remote administration on modern systems. SSH is the standard secure alternative for remote shell access. Connect with SSH Use the username and hostname or IP address of the remote server. Use a different port Only use a custom port if the remote SSH service … Read more

Linux can access remote file systems in several ways. The right method depends on whether you need temporary file copy, interactive browsing, or a mounted network location. Copy files over SSH For one-off file copies, scp or rsync over SSH is usually simpler than mounting a remote filesystem. Mount with SSHFS Unmount it when finished: … Read more

A “cannot mount root filesystem” or “can’t mount root fs” error usually means the kernel cannot access the root partition during boot. This can happen because of an incorrect root device, missing storage driver, filesystem issue, or bootloader configuration problem. Things to check first Was the disk or partition layout changed recently? Was the kernel … Read more

Linux can read many different file systems, but support depends on the kernel, installed packages and whether the file system was cleanly unmounted. Identify the device and file system This shows block devices, mount points and detected file system types. Create a mount point Mount read-only first Mounting read-only is safer when checking an unknown, … Read more

Resizing a Linux filesystem can be useful when a partition or logical volume has become too small, but it should be treated as a careful maintenance task rather than a routine command. Check the current layout These commands help confirm the device name, mount point and filesystem type before making any change. Important safety notes … Read more

Practical first steps for recovering deleted files on Linux, including stopping writes, imaging the device, recovery tools, and SSD/TRIM limitations.

Linux can read and write NTFS drives using the NTFS driver available in modern distributions. This is useful when accessing Windows partitions or external drives. Identify the device Confirm the device name and filesystem type before mounting. Do not guess device names. Create a mount point Mount the NTFS drive Replace /dev/sdXN with the correct … Read more