RedHat

The StAB cluster subscribes to Red Hat, and uses version 6, which is one behind the latest version, version 7.

Being one version behind is typicaly not a problem, as it continues to be fully supported. However, there are software packages that like to use the bleeding edge, and there are admitted problems installing these programs.

Installation of devtoolset-2

There are two ways apparently via RHN Classic or RH Subscription Management, and we choose the latter because there is a useful command-line tool for it.

To install on a node:

ssh node4 'subscription-manager subscribe --pool=8a85f9814ed67b98014eda13ed983c7d'

Note here that we have previously been able to verify the pool ID. Documentation for this can be found at

Click here or Google Red Hat Developer Toolset

This will also enable the appropriate repos for you (though *-source-rpms and *-debug-rpms may be left out).

Problems

outdated repomd.xml warnings

You can get rid of them (i.e. update the repomd.xml) by:

yum clean all
yum update yum*

PYCURL error 7

Note that this could easily occur is the squid server on marvin has failed. Make sure you at least try and restart the squid server on marvin.

This link has a fairly exhaustive for checking errors using tcpdump and nc.

RedHat service types

• A service is usually under one or more of these.
• Some of them are a little old.
• it's probably best to use subscription manager.

man subscription-manager

will work.

The wiki entry on problems with node1 can also be helpful: node 1 issues

ssl connection errors

So the nodes are connected to the internet via the squid proxy service running on marvin. The relevant IP and port numbers are

172.25.64.1:3128

This has always worked quite well since 2016 when it was installed. And the big September 2017 update went through without a hitch. However in Novmber 2017, it started failing with SLL connection errors. Not to EPEL or anything, but to

https://cdn.redhat.com/content/dist/rhel/server/6/6Server/x86_64/optional/os/repodata/repomd.xml

A longish, but somwhat raw troubleshooting page from Red Hat is up at this link.

Considering upgrading to RHEL7

A link for this is solution number 637583

Thoughts

• This could be one heck of an epic upgrade, especially as regards the manually installed software programs (150 or them, some of them very big)
• Most likely it will be the different C library that will cause problems
• Library and linking problems are big ... fear them!

Test with node10

Following solution 637583, we install the upgrade assessemnt software and and run

preupg

which, happily enough, will not install the upgrade but report on what problems are likely to be encountered.

Note, that it takes a while to run, may be 30 mins.