ulimits and my limits
- May
- 24
- Posted by TKH Specialist
- Posted in Analysis, java, linux, Oracle, System Administration, System Resources
Even Linux systems have their limits! One of the systems I manage started throwing a “Too many open files” error in /var/log/messages. No error is good but this error is fixable. A little tuning and the error goes away. On this particular server we were running the Oracle Client and a Java Application, two very […]
read moremd5sum differences on identical systems
- Mar
- 20
- Posted by TKH Specialist
- Posted in Analysis, Troubleshooting
In troubleshooting a problem a colleague noticed that there were md5sum differences in the files of identical systems: ServerOne # md5sum /lib64/libc-2.12.so 27a605fdeaf7c835493a098213c9eec1 /lib64/libc-2.12.so ServerTwo # md5sum /lib64/libc-2.12.so 13e3eb598abd09279efc05e215e77ae2 /lib64/libc-2.12.s Analyzing a hex dump of the .so files showed cyclical differences at matching locations. This is where I began helping to look at the problem. […]
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 moreUsing redhat-support-tool in 10 space
- Oct
- 13
OK, Private IP space, but you should know that 10 space means private IP space. The command redhat-support-tool is useful when working with a Red Hat support ticket. Once a ticket is opened with Red Hat your next step should be to create and attach an sosreport to the ticket. If you don’t then you […]
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 […]
read moreDisk Woes
- Sep
- 10
- Posted by TKH Specialist
- Posted in System Administration, Workstation
I hope to never use this document again but thought it worth documenting in case someone else has need of the information. I powered my desktop off for a planned power outage. When I powered it back on the system failed to boot reporting either “Error 17” or “Error 25”, in short the software raid […]
read moreUnresponsive VMware Images
- Sep
- 10
- Posted by TKH Specialist
- Posted in System Administration
Over the past week I have had two vmware images become unresponsive. When trying to access the images via the vmware console any action reports: rejecting I/O to offline device A reboot fixes the problem, however for a Linux guy that isn’t exactly acceptable. Upon digging a little deeper it appears the problem is with […]
read morescreen your work…
- May
- 27
- Posted by TKH Specialist
- Posted in System Administration, Tools
The Linux screen command is a very useful tool for many reasons. For one you don’t need to worry about losing your session. Sometimes long running jobs with little or no output can lead to your remote session terminating, not usually a helpful thing. Other benefits of the screen command are session logging (thing documentation) […]
read moreCleaning Up Memory Usage
- May
- 06
- Posted by TKH Specialist
- Posted in System Administration
I noticed my Ubuntu desktop was using a rather large portion of available memory. I usually have a lot running on my system, multiple terminals, background jobs, etc so this is nothing unusual. Today however I noticed my system was sluggish so I started digging. Memory use was near 100%. I closed all of my […]
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