[Bi-users] Migration of Bi from CentOS 6 to CentOS 7 (update)

[Kent Engström]

Dear Bi Users,

Update since our email in July:

- You now have ~ 70 nodes running CentOS 7 available. More nodes will
  be moved as needed.

- More software has been built/fixed, for example the Python modules.

- Reported issues with "interactive" and with X11 forwarding to nodes
  have been solved.

- You still use login node bi3.nsc.liu.se to get a CentOS 7 login
  node. The remaining login nodes will be migrated later.

- November is getting closer. Please start testing and moving to
  the CentOS 7 environment in time.


Background
----------

As you may be aware of, Bi was originally supposed to be replaced with
a new cluster this year, but that was postponed for another year. That
means that Bi will outlive the support lifetime of CentOS 6 (ending in
November 2020) and we will have to update the operating system.

As we run CentOS 7 on our other active clusters Tetralith (SNIC),
Sigma (LiU), Stratus/Cirrus (NWP production) and Nebula (MET R&D), we
have decided to use that for Bi too. We have also decided to use the
same software environment (modules, compilers, libraries, scientific
software etc) that we use on those systems, with the smallest possible
changes needed to make it work on Bi.

The bad thing for you in all of this is that you will have to migrate
to a "new cluster" this autumn, without getting access to new
hardware.

The good thing for you is that you will get access to newer software
(both the base OS and the things we provide on top). Also, the step to
the newer environment will be smaller when Bi is replaced with new
hardware.


You should start testing things
-------------------------------

There is a login node bi3.nsc.liu.se available, that runs CentOS 7 and
our new software environment.

As said above, we aim for the Bi environment to mirror what we have on
the other C7 systems, but we are not 100% done yet. Still, we are at a
point where you should login to start testing things, rebuilding your
software, checking out the pre-installed software etc.

We have reserved ~ 70 nodes that runs CentOS 7. When you run sbatch or
interactive from bi3, you will get nodes from that reservation. The
number of nodes running the new environment will be increased as time
goes on. If you find that the number of CentOS 7 nodes stops you from
testing or migrating jobs to CentOS 7, please contact us at
smhi-support at nsc.liu.se.

We recommend you load the buildenv-intel/2018a-eb build environment
module based on the Intel 2018u1 release. If you want to try gcc, we
recommend buildenv-gcc/7.3.0-bare.

If you start testing and discover something that you think should
work, but that seems broken or missing, feel free to send us an email
at smhi-support at nsc.liu.se. We kindly ask you to preface the subject
with "Bi-C7: " to help us distinguish those emails from questions or
problem reports for the current Bi environment.

Best Regards,
 Bi C7 team (Kent, Peter K, Torbjörn)