htop is an interactive system-monitor, but also a process-viewer, process-manager, strace tool and more. Sysadmins may opt to use htop in cases where Unix top does not provide enough information about system processes. htop uses a cursor-controlled interface for sending signals to processes. Just one example where this comes in handy: you don’t have to type […]
Tag Archives: sysadmins
100+ Server Monitoring & Application Performance Monitoring Solutions
Last Updated: Oct 11th 2018, 100+ – Fixed 11 broken links. (including defunct, mergers, acquisitions, or changed links) December 1st 2017 update: 70 100 Top Server Monitoring & Application Monitoring Tools. August 6th 2017 update: 50 70 Top Server Monitoring & Application Monitoring Tools. Back in 2014, I compiled a list of the top 20 server performance monitoring solutions. Largely because I already had […]
How to Kill Inactive SSH Sessions
So, you’ve been disconnected from your server a couple of times which resulted in inactive ssh sessions. You know this because when you use the “w” command, you see something like the following… 22:47:28 up 315 days, 21:09, 2 users, load average: 9.04, 8.17, 7.30 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 ipxxx-xxx-xxx-xxx 23:54 […]
MySQL Performance: Stop hoarding. Drop unused MySQL databases
Last year, I was assisting a new client in addressing MySQL performance issues. There were several areas where MySQL performance issues were addressed. One issue overlooked for several years prior to our communications, was that of keeping around unused databases. Over 15GB of unused MySQL data – a mix of MyISAM and Innodb tables – […]
Linux server performance: Is disk I/O slowing your application?
If your Linux server is bogged down, your first step is often to use the TOP command in terminal to check load averages and wisely so. However, there are times when TOP shows very high load averages even with low cpu ‘us’ (user) and high cpu ‘id’ (idle) percentages. This is the case in the video below, load averages […]
How to fix: At least xMB more space needed on the /boot filesystem
Updated: Aug 13th 2018 List all installed kernel packages with: yum list kernel The kernel in-use will be underlined and cannot be removed: Now to remove unused kernels, install the yum-utils package and use the package-cleanup util: yum install yum-utils package-cleanup –oldkernels –count=2 To make this permanent, edit /etc/yum.conf and add the following line: installonly_limit=2 – – – – – […]
Linux: ncdu and mc to manage large directories
Creating, modifying and deleting files are common tasks performed in any operating system. Even more so by Sysadmins, Developers and Programmers. For the most part, these tasks are fast enough when managing a handful of files. However, on Linux and especially with servers, you may at sometime have to manage millions or even billions of […]
Best Linux Server Distro by main focus/strength
Are you trying to decide on a Linux server distro (distribution)? This article will help guide you based on the strengths of the Linux server distributions available. If you are looking for desktop advice, have a look at Choosing the Best Linux Distro for Desktop. Best Linux Server distro Again, the first rule to remember […]
SCP Linux – Securely Copy Files Using SCP examples
This post includes SCP examples. SCP or secure copy allows secure transferring of files between a local host and a remote host or between two remote hosts. It uses the same authentication and security as the Secure Shell (SSH) protocol from which it is based. SCP on Linux is loved for it’s simplicity, security and pre-installed availability. […]
Linux top: Here’s how to customize it
The top command – referred to below as Linux top – provides a dynamic real-time view of a running system. It can display system summary information as well as a list of processes or threads currently being managed by the Linux kernel. The types of system summary information shown by Linux top command and the order […]