Category: Linux

Atlassian JIRA support for unsupported OpenJDK

Atlassian JIRA does not support OpenJDK. Oracle has changed it licensing for Oracle JDK.  With that in mind, the goal is to use OpenJDK as a replacement for the Oracle JDK. This is possible and easy to do. Search for your jira install %JIRA_HOME/jira/bin/check-java.sh.  On the line that contains "java version" change it to "openjdk version", then restart your install...Read More »

pihole becomes unresponsive

If pihole becomes unresponsive, one reason may be that the diskspace is full. The diskspace may become full from an excessively large pihole database and or /var/log entries.  In a recent case, both were the cause.  Stopping the services and truncating the logs in /var/log and deleting the database worked in this case.  The following logs were large, but I…

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pihole reset all stats

There may be a time where you want to have a fresh dashboard without the stats and logs.  A case maybe a misconfigured NIC that may dump millions of DNS queries into the logs.  Yup I have seen this happen. Whenever you need to reset the pihole stats and logs that display on the /admin dashboard, the following options will…

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Create systemd services for Atlassian Apps

While working with the Atlassian products over the years, a pattern emerges. Even though there are distinct differences in their setup and configurations, the installation process can be generalized. One of the post-installation considerations to make is in the manual creation of a service.  The benefit of a service is that it will automate the running of the application, rather...Read More »

CentOS 7 df command hangs

The df command is useful in reporting disk space usage.  However, recently encountered a system that would hang after issuing the df command.  A ctl c or ctl z would not escape this annoyance.  The issue was quickly resolved by reinstalling stystemd. After reinstalling systemd, the df command was reissued and was quite responsive. Source https://serverfault.com/questions/911811/centos-7-df-started-to-hangRead More »

The cd command in CentOS 7

I have been working in a CLI environment for many years, so the cd "change directory" command is nothing new to me; however, an accidental typo presented an unexpected result.  Instead of typing "cd .." which would transverse back one directory, a user typed only "cd" with the intention of pasting from the clipboard the rest of the path.  The...Read More »

VIM: Preserve File Date with Touch

I had a single file I needed to modify but didn't want to modify the date of the file.  It was a minor change to the file, so I wanted to maintain the file date for posterity.  In any case, I learned the vim does not provide this functionality, but touch would and quite easily.  With that said, I am...Read More »

Determine which processes are using swap in Linux

Some servers may have several applications, each running in their own allocated piece of RAM and SWAP.  It seems easy enough to use `top` to determine memory usage, but it wasn't so obvious (to me) as to how to determine swap usage.  A nifty little command called smem to the rescue. So what is smem?  It is a "Report memory...Read More »