Category Archives: Linux

Linux – Vim file editor cheat sheet

How to navigate in a Linux file editor VI, pasting a cheat sheet. There are many more options but this is all i usually need to maneuver around. :wq Save file and quit :q! Exit without saving :set nu Display … Continue reading →...

Posted in Linux | Tagged , | Leave a comment

Secure Wipe a File with DD Linux

You may have a need to secure erase a file with the Linux DD command. When you erase a file with the rm command the pointer to the file is erased but the file still exists on the file system … Continue reading →...

Posted in Linux | Tagged , , | Leave a comment

Active Directory permissions required to join Linux and Windows Computers to a Domain

I recently ran into an issue where i needed to create a service account with bare minimum permissions to add a Windows and a Linux server to a domain. Windows was fairly easy to join it only requires the 5 … Continue reading →...

Posted in Linux, Microsoft | Tagged , , , | Leave a comment

How to tar and untar files and folders in Linux

Here is a quick cheat sheet how to compress and extract files/folders in CentOs Linux.  If you are extracting to a specific folder you have to create the folder ahead of time with mkdir /tmp/data/ or the command will not … Continue reading &r...

Posted in Linux | Tagged , , , | Leave a comment

How to configure a redis 2.8 cluster in CentOS 6.7

I have been involved in rolling out the Cherwell ticketing system and I thought I would share some notes around the Redis configuration.  Redis is used when you install Cherwell in a high availability mode.  It is used to store … Continue re...

Posted in Linux | Tagged , | Leave a comment

iPerf Network performance comparison between Virtual Machines on ESXi6

I finally found some time to run a series of iPerf network performance tests between Windows server 2008 R2, Windows 2012 and a Linux Debian virtual machines. The tests compare bandwidth throughput between vmxnet3, e1000 going through a 1Gbit and &he...

Posted in Linux, Networking, VMware | Tagged , , , , , , , , | Leave a comment

Detecting Ephemeral Port Exhaustion in Windows 7 / 8 / 2012

Ephemeral ports are ports that start at a higher range then regular ports. For example when compared to a web server that listens on port 80, ephemeral ports start from 49152 for Windows 2008 R2.  If there are scripts or … Continue reading &r...

Posted in Linux, Networking | Tagged , , , , , , , | 4 Comments

Set up and troubleshoot SNMP on an ESXi 5.5 host

Here are some quick notes how to troubleshoot and set up SNMP on an ESXi host. The below also includes how to install snmpwalk and request info from an snmp server. STEPS HOW TO PROPERLY SET UP SNMP ON AN … Continue reading →...

Posted in Linux, Networking, Scripting, VMware | Tagged , , , , , , , , | Leave a comment

Testing TCP/UDP port connectivity in VMware ESXi 5.x Host

There may be times when you need to test TCP/UDP port connectivity from an ESXi host, here are some useful netcat commands. If you see no output from these commands it means the connection failed. Test TCP Port 902: ~ … Continue reading →...

Posted in Linux, VMware | Tagged , , | Leave a comment

How to add a cron job to VMware ESXi 5.x

Here is a quick way that you can add a cron job in ESXi 5.x. You will notice that there are already jobs in here that run on a schedule by default, the last line is new. Edit the below … Continue reading →...

Posted in Linux, Scripting, VMware | Tagged , , , | Leave a comment