Monthly Archives: March 2014

SSE optimization for erasure code in Ceph

The jerasure library is the default erasure code plugin of Ceph. The gf-complete companion library supports SSE optimizations at compile time, when the compiler provides them (-msse4.2 etc.). The jerasure (and gf-complete with it) plugin is compiled multiple times with … Continue reading

Posted in ceph | 2 Comments

Testing CPU features with Qemu

The Ceph erasure code plugin must run on Intel CPU that have no SSE4.2 support. A Qemu is run without SSE4.2 support: qemu-system-x86_64 -machine accel=kvm:tcg -m 2048 \ -drive file=server.img -boot c \ -display sdl \ -net nic -net user,hostfwd=tcp::2222-:22 … Continue reading

Posted in Uncategorized | Leave a comment

Your first exabyte in a Ceph cluster

$ rbd create –size $((1024 * 1024 * 1024 * 1024)) tiny $ rbd info tiny rbd image ‘tiny’: size 1024 PB in 274877906944 objects order 22 (4096 kB objects) block_name_prefix: rb.0.1009.6b8b4567 format: 1 Note: rbd rm tiny will take … Continue reading

Posted in ceph | Leave a comment

The footprints of 192 Ceph developers

Gource is run on the Ceph git repository for each of the 192 developers who contributed to its development over the past six years. Their footprint is the last image of a video clip created from all the commits they … Continue reading

Posted in ceph, git, gource | Leave a comment

working with git submodules in Ceph

The gf-complete and jerasure libraries implement the erasure code functions used in Ceph. They were copied in Ceph in 2013 because there were no reference repositories at the time. The copy was removed from the Ceph repository and replaced by … Continue reading

Posted in ceph, git | Leave a comment

BIOS and console access via VNC

The AMT of an ASRock Q87M motherboard is configured to enable remote power control (power cycle) and display of the BIOS and the console. It is a cheap alternative to iLO or IPMI that can be used with Free Software. … Continue reading

Posted in AMT, VNC, vPro | Leave a comment

Micro PDP-11

Posted in Uncategorized | 2 Comments

Vue subjective de la naissance de l’Erasure Code dans Ceph

L’erasure code, c’est aussi le RAID5, qui permet de perdre un disque dur sans perdre ses données. Du point de vue de l’utilisateur, le concept est simple et utile, mais pour la personne qui est chargée de concevoir le logiciel … Continue reading

Posted in Uncategorized | Leave a comment

Benchmarking Ceph jerasure version 2 plugin

The Ceph erasure code plugin benchmark for jerasure version 1 are compared after an upgrade to jerasure version 2, using the same command, on the same hardware. Encoding: 5.2GB/s which is ~20% better than 4.2GB/s Decoding: no processing necessary (because … Continue reading

Posted in ceph | Leave a comment

OpenStack Upstream Training in Atlanta

The OpenStack Foundation is delivering a training program to accelerate the speed at which new OpenStack developers are successful at integrating their own roadmap into that of the OpenStack project.  If you’re a new OpenStack contributor or plan on becoming … Continue reading

Posted in openstack | Leave a comment