Setting up a Globus Online Service

The School storage is continuously increasing and datasets of many terrabytes are no longer exceptional. One of the big problems with large datasets is how to transfer them from one system to another. One of our research groups collects micro tomography datasets of the order of tens of terrabytes. These …

Deleting too many files

CephFS is now an integral part of the School of GeoScience's IT infrastructure. It provides both personal and group storage for windows, mac and linux users. Since our first disaster due to running out of resources it has been running very reliably and it provided all the benefits we had …

Conda on LCFG Managed Ubuntu systems

Conda is the name of the package manager used with the data science distribution anaconda. It is available for Linux, Windows and Mac systems and is heavily used for managing scientific software environments. In the past we required our users to download and install conda themselves. Earlier versions of conda …

Evolution and Exchange MFA at Uni of Edinburgh

The University of Edinburgh is piloting multifactor authentication for Office 365. This works with the GNOME evolution mail/calendar application and the EWS plugin. In evolution create a new mail account of type Exchange Web Services and username: UUN@ed.ac.uk host URL: https://outlook.office365.com/EWS/Exchange …

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 …

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 …