Openbsd HowTo - Linux / Unix Q & A from nixCraft

How to find disk I/O latency with ioping monitoring tool on Linux

last updated September 21, 2017 in FreeBSD, Linux, Mac OS X, OpenBSD, UNIX

How do I monitor disk I/O latency in real time on Linux, FreeBSD, OpenBSD, and MacOS operating system?

How to summarize detailed system resource usage for given command on a Linux or Unix

last updated December 8, 2015 in CentOS, Debian / Ubuntu, FreeBSD, Linux, Mac OS X, Troubleshooting, UNIX

How do I determine the system resource usage during of execution of a particular command on a Linux, OS X Unix, BSD and Unix-like operating system?

Connect To Amazon AWS EC2 Instance From a CentOS / RHEL Using SSH Client

last updated June 23, 2014 in Amazon Cloud Computing, CentOS, Linux, OpenBSD, RedHat and Friends, UNIX

I have created/launched Amazon Machine Image (AMI) instance powered by a CentOS/RHEL/Red Hat Enterprise Linux. How can I connect to my instance using OpenSSH Linux/Unix/OSX ssh client?

scp: Do not Overwrite Existing File On Linux or Unix System

last updated May 10, 2013 in BASH Shell, Commands, Linux, UNIX

I am a new Linux user. I use scp to upload files to net-storage provided CDN company. I do not want to overwrite the existing files. How can I prevent overwriting of files when using scp command under Linux, Mac OS X or Unix like operating systems?

Vi / Vim: Wipe and Undo All Changes Since Opening a File

last updated April 28, 2013 in Linux, UNIX, Vim

I am a new vi / vim text editor user and I know how to quit without saving changes. What if I want to wipe out all of the edits I have made in a session and get back to the original file? How do I wipe all changes since opening a file?

SSH: WARNING: UNPROTECTED PRIVATE KEY FILE! Error and Solution

last updated January 26, 2017 in Amazon Cloud Computing, Linux, Mac OS X, OpenBSD, Suse, Troubleshooting, UNIX

I‘m setting up server on an Amazon EC2 compute instance powered by Suse Enterprise Linux server. I am using the following command to login into the my EC2 compute from OS X/Ubuntu desktop:

ssh -i suse-ec2-server-jp.pem root@ec2-xx-yy-zzz-yyy.compute-1.amazonaws.com

I am getting the following error:
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: UNPROTECTED PRIVATE KEY FILE! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions 0440 for 'suse-ec2-server-jp.pem' are too open. It is recommended that your private key files are NOT accessible by others. This private key will be ignored. bad permissions: ignore key: suse-ec2-server-jp.pem Password:

How do I fix this problem and login using ssh command?

Linux / Unix Bash Shell List All Builtin Commands

last updated January 25, 2018 in BASH Shell, Linux, UNIX

Builtin commands contained within the bash shell itself. How do I list all built-in bash commands on Linux / Apple OS X / *BSD / Unix like operating systems without reading large size bash man page?