Author Archives: Loic Dachary

HOWTO migrate an AMI from Essex to a bootable volume on Havana

A snapshot of an Essex OpenStack instance contains an AMI ext3 file system. It is rsync’ed to a partitioned volume in the Havana cluster. After installing grub from chroot, a new instance can be booted from the volume.

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Backporting with magit

Ceph uses GF-Complete stable branch (v1). Modifications required by Ceph were proposed to the master branch. While waiting for the corresponding pull request to be reviewed, a temporary branch (v1-ceph) was created in the Ceph name space for immediate use. … Continue reading

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Merging with magit and ediff

The jerasure v2 branch is merged into the v2-ceph branch.

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Celebrate Firefly and Icehouse

If you’re in Atlanta Sunday 11th, may 2014 evening, for the OpenStack summit or any other reason, join us to celebrate the OpenStack Icehouse release and the Ceph Firefly release. There will be both OpenStack and Ceph developers present and … Continue reading

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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

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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

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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

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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

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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

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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

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