Courtesy of Pete in work. To enable hostname auto completion in Bash, do the following: dig pop @dns.server.tld axfr | awk '$4 ~ /\yA\y/ && gsub(/.$/,"",$1) {print $1}' > ~/.hosts If you would prefer to filter out hosts e.g. dev and... » More
The default user and password combination for a Dell iDRAC interface is root / calvin It can be manually reset when logging in to the web interface but when doing many machines at once and many actions at the same time the racadm tool is handy. To... » More
Install the prerequisites. Below works for Debian-based distros such as Ubuntu/Mint: Install python libraries: Example code below shows making a connection, getting the names of some child nodes and pulling info from each of those child... » More
Ubuntu 18.04 includes check-mk in the repository version but it is an older version 1.2.8 (at the time of writing). Download check mk raw (get the latest stable URL from the website) : Try installing it: You may get dependency issues which can... » More
In the update from iDRAC 8 to iDRAC 9 it has been infuriating searching the 'Storage' menu only to discover that the storage is managed under 'Configuration > Storage Configuration' I'm convinced the user experience could be better! At the very... » More
Journald logs can be cleared by timescale or size as follows.
Keep only 5 days worth of logs
journalctl --vacuum-time=5d
Retain only the past 500 MB:
journalctl --vacuum-size=500M
The puppet agent can be disabled from running with: And it can be re-enabled with: But to check if puppet is currently disabled there is no check command. Instead look for the existence of the agent_disabled.lock file under: For the systems I... » More
I sometimes want to omit directories from my disk usage (du -sh *) checks. This includes virtual files systems such as proc / dev and also mounts to other filesystems (data in the example below). This is what works for me: The equals sign appears to... » More
I was checking the memory on approximately 140 servers using ansible: but the output appears over several lines e.g. but what I wanted was the server name and the total memory available. So I first grepped the output to remove the lines I didn't... » More
In a Cloudera cluster we had a few nodes reporting the following error message in the logs under hadoop-cmf-hdfs-DATANODE-whatever.com.log.out The error included: Datanode denied communication with namenode because the host is not in the... » More
Courtesy of Pete in work. To enable hostname auto completion in Bash, do the following: dig pop @dns.server.tld axfr | awk '$4 ~ /\yA\y/ && gsub(/.$/,"",$1) {print $1}' > ~/.hosts If you would prefer to filter out hosts e.g. dev and... » More
