Planet Ceph

Aggregated news from external sources

  • September 23, 2014
    HOWTO extract a stack trace from teuthology

    When a teuthology test suite fails on Ceph, it shows in pulpito. For instance there is one failure in the monthrash test suite with details and a link to the logs. By removing the teuthology.log part of the link a … Continue reading

  • September 20, 2014
    Running python rados tests in Ceph

    When Ceph is built from sources, make check will not run the tests. A minimal cluster is required and can be run from the src directory with: CEPH_NUM_MON=1 CEPH_NUM_OSD=3 ./ -d -n -X -l mon osd The test can … Continue reading

  • September 19, 2014
    Ceph placement group memory footprint, in debug mode

    A Ceph cluster is run from sources with CEPH_NUM_MON=1 CEPH_NUM_OSD=5 ./ -d -n -X -l mon osd and each ceph-osd uses approximately 50MB of resident memory USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND loic 7489 1.7 … Continue reading

  • September 17, 2014
    Running node-rados from sources

    The nodejs rados module comes with an example that requires a Ceph cluster. If Ceph was compiled from source, a cluster can be run from the source tree with rm -fr dev out ; mkdir -p dev CEPH_NUM_MON=1 CEPH_NUM_OSD=3 \ … Continue reading

  • September 16, 2014
    HOWTO test a Ceph crush rule

    The crushtool utility can be used to test Ceph crush rules before applying them to a cluster. $ crushtool –outfn crushmap –build –num_osds 10 \ host straw 2 rack straw 2 default straw 0 # id weight type name reweight … Continue reading

  • September 10, 2014
    HOWTO test teuthology tasks

    The Ceph integration tests run by teuthology are described with YAML files in the ceph-qa-suite repository. The actual work is carried out on machines provisioned by teuthology via tasks. For instance, the workunit task runs a script found in the … Continue reading

  • August 31, 2014
    What cinder volume is missing an RBD object ?

    Although it is extremely unlikely to loose an object stored in Ceph, it is not impossible. When it happens to a Cinder volume based on RBD, knowing which has an object missing will help with disaster recovery. The list_missing command … Continue reading

  • August 24, 2014
    Update: OpenStack Summit Paris 2014 – CFS

    An update on my talk submission for the OpenStack summit this year in Paris: my speech about Ceph performance analysis was not chosen by the committee for the official agenda. But at least one piece of good news: Marc’s talk will be part of t…

  • August 14, 2014
    Tell teuthology to use a local ceph-qa-suite directory

    By default teuthology will clone the ceph-qa-suite repository and use the tasks it contains. If tasks have been modified localy, teuthology can be instructed to use a local directory by inserting something like: suite_path: /home/loic/software/ceph/ceph-qa-suite in the teuthology job yaml … Continue reading

  • August 10, 2014
    A new Ceph mirror on the east coast

    I’m glad to announce that Ceph is now part of the mirrors iWeb provides.

    It is available in both IPv4 and IPv6 by:

    The mirror provides 4 Gbps of connectivity and is located on the eastern coast of Canada, more precisely in Montreal, Quebec.

    We feel this complements very well the principal ceph mirror at located on the west coast and the european mirror on

    Feel free to give it a try and let me know if you see any problems !

  • August 2, 2014
    OpenStack Summit Paris 2014 – CFS

    The Call for Speakers period for the OpenStack Summit from 03. – 07.11.2014 in Paris ended this week. Now the voting for the submitted talks started and ends at 11:59pm CDT on August 6. (6:59 am CEST on 7. August).I’ve submitted a talk to the stor…

  • August 2, 2014
    Temporarily disable Ceph scrubbing to resolve high IO load

    In a Ceph cluster with low bandwidth, the root disk of an OpenStack instance became extremely slow during days. When an OSD is scrubbing a placement group, it has a significant impact on performances and this is expected, for a … Continue reading