#+TITLE: Optimized & Reproducible HPC Software Deployment

https://fosdem.org/2017/schedule/event/hpc_deployment_guix/
Sat. 11:30, H.2213

* current HPC software environments are broken
** distros are old and inflexible, not upgraded
** thus, sysadmins write their own modules
** hand-maintained modules break, still inflexible
** modules may be removed behind your feet
** thus, users hand-build software in $HOME
** possibly using language-specific package managers
** => it's a mess
* fixing this chaos
** first approach: easybuild & spack
*** layered on top of the existing distro
*** good: packaging work is shared among HPC users, some QA
*** bad: everyone builds in $HOME -> waste of resources
*** bad: uses host tools -> not reproducible [screenshots]
** second approach: app bundles
*** we have the bits, not the source
*** 100% reproducibility, but prevents experimentation
*** wrong level of abstraction: we don’t care about bits, but about packages
** third approach: can we have our cake and eat it too?
* Guix
** what it is
** example commands
** isolated builds: 100% reproducible
** reproducible *yet* customizable [RepPar paper]
** package variants, personal packages
** sharing environments
- symbolic sharing: manifests
- share the bits: “guix pack” (with Docker support)

* HPC & non-root usage
** the problem: guix-daemon runs as root because that's the only way to get repro build envs
** solutions:
*** running guix-daemon as non-root: doesn't work
*** user namespaces: unfortunately not widely available
*** relocation: yay!