RHEL: Adding Disk Space
- Jul
- 31
- Posted by TKH Specialist
- Posted in Uncategorized
So your Disk is getting full or worse already full. Here’s a step-by-step approach to troubleshoot and resolve this issue: First, verify the current state of your volume group: vgdisplay vc_name This will show you the details of the ‘rhel’ volume group, including free space. Check the status of the new disk: Ensure that /dev/sdb […]
read moreIssues with Tomcat7 on RHEL7
- Feb
- 01
- Posted by TKH Specialist
- Posted in tomcat
On RHEL7, up until tomcat v7.0.59 Redhat maintained backwards compatibility with RHEL6 structures. Once you upgrade to tomcat 7.0.70-x all that changes. Two things specifically: First: One big change is the use of $CATALINA_OPTS, if you have multiple lines defining various $CATALINA_OPT properties your installation will break. Once you upgrade you must specify all of […]
read moreInstalling Splunk agent for log collection
- Feb
- 13
- Posted by TKH Specialist
- Posted in Logging, Troubleshooting
Splunk agent downloads and directions for enabling Splunk log collection. Overview: This page describes the initial process for Splunk log collection. The only server-side requirements are 1) installation of the Splunk agent 2) configuration of that agent to ask the Splunk deployment server for its configuration. A necessary follow-up step is a list of servers […]
read moreCopying a file to multiple locations
- Jan
- 17
- Posted by TKH Specialist
- Posted in bash, System Administration
I thought this was cool enough to share. I have not had to use it however so I doubt it is all that useful 😉 xargs -n 1 cp -v foo.txt<<<“/tmp1/ /tmp2/ /tmp3/” Here we are copying one file named foo.txt to multiple directories called /tmp/1/, /tmp/2/, and /tmp/3 using xargs. The xargs command construct […]
read moreDisable All User Login Access
- Jan
- 05
- Posted by TKH Specialist
- Posted in System Administration
There are occasions when you want to make sure users can not log into a system. This can be due to a maintenance period or I have used it as part of the process for retiring a system. It is simple enough but I thought it worth documenting for prosperity. # cd /{root of user […]
read moreYum Rollbacks
- Dec
- 21
- Posted by TKH Specialist
- Posted in System Administration
Very occasionally installing a package or updates with yum can have unexpected results. Fortunately yum provides the ability to roll back anything it installs. Here is an example of what these commands look like: # yum history Loaded plugins: package_upload, product-id, search-disabled-repos, security, subscription-manager ID | Login user | Date and time | Action(s) | […]
read moreSubnet Cheat Sheet
- Dec
- 14
- Posted by TKH Specialist
- Posted in networking, System Administration
Subnet Mask Cheat Sheet Posted here because 95% of the networks are the same and when I encounter a different one I have to think about it…not any more! See RFC 1878 for more details & information. Addresses Hosts Netmask Amount of a Class C /30 4 2 255.255.255.252 1/64 /29 8 6 255.255.255.248 1/32 […]
read moreNetwork Interface Name in rhel7
- Dec
- 07
- Posted by TKH Specialist
- Posted in networking, RedHat 7, rhel 7
Anyone who has installed rhel7 knows how annoying it is to check you network and not see eth0. Perhaps it is just me then… Regardless here are instructions on how to change it: First you need to know the name of the network adapter in use, you can look in /etc/sysconfig/network-scripts/ifcfg-eno##### or run this command: […]
read moreyum Invalid System Credential error
- Sep
- 30
- Posted by TKH Specialist
- Posted in redhat, rhel 6, rhel 7, Satellite, System Administration
I ran across the following yum error after migrating a system from being a client of Satellite 5.6 to Satellite 6.1. First here is the error: # yum update Loaded plugins: package_upload, priorities, rhnplugin, search-disabled-repos, security, subscription-manager There was an error communicating with RHN. RHN Satellite or RHN Classic support will be disabled. Error Message: […]
read moreWorking with Repositories
- Sep
- 29
- Posted by TKH Specialist
- Posted in redhat, System Administration
Pulling packages from multiple sources can lead to problems. If you are running rhel and have epel enabled an update could inadvertently pull down a newer version from the wrong repository. This doesn’t always cause a problem, but it can. If you need to tfind all the epel packages on your system, here is how […]
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