yum Invalid System Credential error

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: […]

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Working with Repositories

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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Don’t Panic Kernel!

You do your best to keep your systems running, but eventually something is going to happen (read you are going to do something) that leads to a Kernel Panic.  Every System Administrator fears a Kernel Panic at some point in their career, but it is never a good idea to panic over one!  Here are […]

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To reboot or not to reboot?

You have patches to apply, we all know that if there are kernel patches that you need to (or at least should) restart/reboot the server.  But what about other packages?  There are a few non-kernel patches which can cause havoc if you spply them and do not reboot the server.  The biggest package that most […]

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6GB free = 100% disk usage?!

What to do when you have plenty of available disk space but the system is telling you the disk is full?!  I was working on a server migration, moving 94GB of user files from the old server to the new server.  Since we aren’t planning on seeing a lot of growth on the new server, […]

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OCI on RHEL6

Our developers had to have OCI.  Now that I got that out of the way. 😉 We use Oracle as our DB for most applications (calm down, like you couldn’t have figured that out).  In setting up a new application server for a custom application it came to my attention that the application used oci […]

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Pain often equals Progress

It has been one of those weeks.  Not fun, to many hours worked, personal events missed, you know the kind of week I am talking about.  If not…what do you do for a living?! Despite all the pain and stress this week has resulted in Progress, an increased understanding of certain products and new ways […]

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The Root of Missing Mail

Like all conscientious system administrator I like to keep tabs on my servers.  One way of doing this is checking root’s email daily.  This is a great idea if you have a few servers and never take vacation!  I manage close to 100 servers, so I need a more efficient way of “hearing” my servers […]

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Yum that was useful!

Pardon the humor.  Just a collection of useful yum commands that are useful to have around but I don’t always remember off the top of my head.  I’ll be adding to this post over time. How to list the files installed by a yum package You will need ‘repoquery‘ which is part of ‘yum-utils‘.  If […]

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Flush This!

I came across this today and learned something new so thought I would share it here. After killing 2 processes that had hung I noticed the following in the ps output: root       373     2  0 Jun11 ?        00:00:00 [kdmflush] root       375     2  0 Jun11 ?        00:00:00 [kdmflush] root       863     2  0 Jun11 ?        00:00:00 [kdmflush] […]

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