12 Feb 2020, 00:00

CS3 conference 2020

CS3 conference 2020

I recently attended the CS3 conference in Copenhagen. I did a talk about our experiences from running ceph in production for almost 3 years, and here is a link to the slides from my talk

12 Feb 2020, 00:00

Some useful GPG commands

Some useful gpg commands

I recently ran into a problem with some gpg encrypted file, where the files were encrypted with another key than they were supposed to. Therefore I had to reencrypt them with another key. Every time I run into an unusual task with OpenGPG I find myself banging my head into a wall of useless documentation. Here’s some of the useful commands I found which let me resolve the issue:

First I had to find out what keys the file was actually encrypted with.

gpg --list-packets file.gpg - lists contents of a gpg encrypted package - including the key IDs used for encrypting the file. (The man page is of course less useful, since it only says “List only the sequence of packets. This command is only useful for debugging.” - but I haven’t found another way to do what I want)

% gpg --pinentry-mode cancel --list-packets <file>.gpg 2>&1 - if you only want to see which keys a file is encrypted with. (note, it will list the keys to STDERR, so therefor I added the redirect to STDOUT so I could grep for the key I was looking for)

% gpg -k --keyid-format short and % gpg -k --keyid-format long - There is a long and short format for GPG keys. If you want to see the short or long format for the keyid when listing keys, add the —-keyid-format option.

Note: if you always want to print for instance long format, you could add keyid-format long to ~/.gnupg/gpg.conf

Want to know the fingerprint of the subkeys? Use gpg -K --with-subkey-fingerprint --keyid-format none

A few useful links:

13 Feb 2019, 00:00

CS3 conference 2019

Summing up the CS3 conference 2019

This year started with a visit to Rome and the 5th edition of the CS3 (cloud services for synchronisation and sharing) - a yearly European conference that started as a workshop between Universities, National Research and Education networks and Research Centres in an attempt to exchange experiences in extending traditional storage technologies to the cloud.

This was my second visit to the conference, last time was two years ago, and I worked for the University of Oslo and visited primarily because of my interest in sync and sharing solutions. This time, I visited on behalf of my current company, and I have moved a bit down the stack, and I held a short presentation on how we are building an open source load balancer for our next generation storage clusters. I’m not going to say a lot about my talk, I hope it went OK.

The conference itself is packed with content. It is a single track conference spanning three days, and a total of almost 60 talks - which is a LOT! - I’m just linking to a couple of my favourite talks and a couple of observations.

Opening keynote by Davide Salomoni

  • Davide Salomoni from INFN did a great job explaining some of the challenges with the current state of machine learning. Great to see a talk about machine learning that is genuinely interesting and not “hyped” in any ways.

The Magic Pocket - How dropbox is handling large data sets

by Said Babayev and Martin Meusburger This was an interesting talk, because it is always fun to hear about how large companies do operations. It is interesting to hear how they have managed to use SMR-drives in production. We have tried, but gave up, but then dropbox is on an completely different scale than us…

Scaling Tightly Coupled Algorithms on AWS

by Scott Eberhardt While I’m not convinced yet that it is a good idea to run your HPC workloads on Amazon, the talk was mostly about scaling, and that’s what made the talk interesting.

One thing I would love to see at a future conference is more attendees from the nordic countries. There is a lot of exiting things going on here, but I feel we are missing out on a bit of the cooperation that happens between the

Rome is a nice city, but January can be cold, rainy and windy. However, I got a few hours of sightseeing in nice weather on Thursday afternoon before I had to return home. The highlight was definitely seeing the Jackson Pollock exhibition at Complesso Del Vittoriano.