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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Kerberizing RHEL Server

Notes from Plone… yum install krb5-workstation pam_krb5 -y # if krb5.conf is present we should get a fresh copy mv /etc/krb5.conf /etc/krb5.conf.bak yum reinstall krb5-libs -y sed -ie ‘s/example.com/FQDN/g’ /etc/krb5.conf sed -ie ‘s/EXAMPLE.COM/FQDN/g’ /etc/krb5.conf fqdn=`hostname –fqdn`; echo ” ank -randkey host/$fqdn@FQDN ktadd -k /etc/krb5.keytab host/$fqdn@FQDN “; — OR — kadmin netid/admin@FQDN addprinc -randkey host/$fqdn ktadd […]

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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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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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My MySQL Cheat Sheet

I know, man.  No, I mean I know I could use ‘man pages’!  Or I could just ‘google it’ but then it isn’t mine.  Since I do not have time for a complete brain-dump this MySql “cheat sheet” will grow over time.  Feel free to add your favorite MySql commands in the comments, if their […]

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Putting ‘lsof’ to use

lsof is a powerful tool that has proven very userful over the years in troubleshooting and forensic investigations.  Here are some useful lsof command examples: In this example we are looking at all the files a given process has open (pid=1655 here this is the zabbix agent) lsof -p 1767 Note you can clean up […]

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memcached

In support of the Kuali project. Setting up true fail over for the Kuali application servers.  Currently if a node went down, the user would need to re-authenticate.  The following procedure configures the system so it can lose a node and the users on that node will not lose their session. My part on the […]

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Extended ACLs

To remove permanently ACL from a file: # setfacl -bn file.txt To remove permanently ACL from an entire directory: # setfacl -b –remove-all directory.name To overwrite permissions, setting them to rw for files and rwx for dirs $ find . ( -type f -exec setfacl -m g:mygroup:rw ‘{}’ ‘;’ ) -o ( -type d -exec […]

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