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: apt-get install libzookeeper-mt-dev Install python libraries: pip install zkpython pykeeper Example code below shows making a connection, getting the names of some... » 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) : wget... » 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: puppet disable "Some message here" And it can be re-enabled with: puppet enable But to check if puppet is currently disabled there is no check command. Instead look for the existence of the... » 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: du... » More
I was checking the memory on approximately 140 servers using ansible: ansible --user root -k -i servers.list -m shell -a "free -h; mysql" test but the output appears over several lines e.g. server103.domain.dev | SUCCESS | rc=0 >> total used... » 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
