School of GeoSciences Ceph Architecture

In one of my previous posts I outlined the ceph setup used in the School of GeoSciences. In this post, I would like to describe how the various bits fit together in some more detail. The diagram above shows a simplified version of our computing setup. Broadly speaking we distinguish …

June Ceph Update - the Queen's CURRY

We had the opportunity to try out a cold start of all our servers located in the College Server Room on the weekend. We shut down all machines on Friday 11th June to allow contractors to work on the electricity supply on Saturday. From my perspective the most interesting aspect …

Remote Filesystem Experiemnts

Now that our CephFS file store is in production and LCFG managed Ubuntu is available I began to experiment with running Samba on Ubuntu. The good news is that the LCFG samba component pretty much worked out of the box. The minor tweak that was required is going through the …

Ceph Science Meeting - March 2021

Yesterday, I attended the ceph science meeting. I noticed the meeting was advertised on the ceph user mailing list and decided to go along to see what it is about. Ceph sysadmins from various institutions across the world attended to exchange information and discuss issues arising with scientific workloads. The …

School of GeoSciences aptly package repository

The School of GeoSciences is running an aptly debian package repository. The following repositories are available: ubuntu ubuntu mirror inf informatics mirror uoe UoE package repository with component uoe world world package repository with component world geos School of GeoSciences repository with component geos All repositories and mirrors are available …

Anatomy of a CephFS Disaster

This post describes in detail how we ended up with a damaged CephFs and our attempts to fix it. Background On 3rd September we scheduled some downtime to reconfigure the network of our ceph cluster. Prior to that we used two networks: one frontend network used by the ceph clients …

Using Singularity to containerise a Scientific Model

I was asked to install the parallel ice sheet model (PISM) by one of our researches. PISM is modern high-order physics ice sheet model that is written in C++ and uses MPI and PETSc. All our Linux machines are LCFG managed Scientific Linux 7 machines. PISM is built from source …

School of GeoSciences File Storage

Providing secure, reliable, performant file storage is one of the fundamental services an IT team provides. This post describes in detail how the new CephFS based storage at the School of GeoSciences works. All our Linux machines, servers, compute boxes and desktops are running Scientific Linux and are managed using …

Machines with Error

I went to an excellent panel discussion on AI biases, failures and fairness hosted by the University of Edinburgh. This presentations and the following discussion was very interesting, although I think it didn't quite hit the spot I was looking for. A lot of the discussion was on biases. Biases …

Preparing for another Strike

So we are going on strike again. In addition to the pension dispute which is still not resolved, we are also striking for better pay, working conditions, workload and the gender pay gap. Both issues are hugely important. But at the same time, it is ridiculous that they need to …