Posts By: jonny

Changing Dell iDRAC Password with racadm

Shell

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 change the password use: racadm -r 192.168.1.23 -u… Read more »

Querying Zookeeper from Python

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 nodes:

Unfortunately I can’t get this installed on CentOS.    

Install check_mk on Ubuntu 18.04

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 be resolved with:

Then try the install again:

Read more »

iDRAC 9 Set Physical Disk to Non-RAID

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 least a link through for configuration.

Clearing old Journald Logs

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

Checking if Puppet is Disabled

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 was checking this was at:

Exclude Directories for Disk Usage (du)

ncdu

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 be optional and worked both ways for me…. Read more »

Joining Multi-line Output with Paste

Shell

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 want e.g.

leaving me with two lines of… Read more »

Datanode denied communication with namenode

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 include-list: : DatanodeRegistration One solution could be to ‘Refresh Node List’ as shown in the screenshot below. Find it by clicking… Read more »

Set NTP Server on Windows Domain Controller

On the Windows Domain Controller I checked the current NTP settings with:

  I tried a few alternative commands and got errors such as “the rpc server is unavailable”. The command that worked was:

After issuing that command I could see the ntp server listed when re-running the command:

As shown below.