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diff --git a/src/ceph/doc/rados/operations/erasure-code-jerasure.rst b/src/ceph/doc/rados/operations/erasure-code-jerasure.rst deleted file mode 100644 index e8da097..0000000 --- a/src/ceph/doc/rados/operations/erasure-code-jerasure.rst +++ /dev/null @@ -1,120 +0,0 @@ -============================ -Jerasure erasure code plugin -============================ - -The *jerasure* plugin is the most generic and flexible plugin, it is -also the default for Ceph erasure coded pools. - -The *jerasure* plugin encapsulates the `Jerasure -<http://jerasure.org>`_ library. It is -recommended to read the *jerasure* documentation to get a better -understanding of the parameters. - -Create a jerasure profile -========================= - -To create a new *jerasure* erasure code profile:: - - ceph osd erasure-code-profile set {name} \ - plugin=jerasure \ - k={data-chunks} \ - m={coding-chunks} \ - technique={reed_sol_van|reed_sol_r6_op|cauchy_orig|cauchy_good|liberation|blaum_roth|liber8tion} \ - [crush-root={root}] \ - [crush-failure-domain={bucket-type}] \ - [crush-device-class={device-class}] \ - [directory={directory}] \ - [--force] - -Where: - -``k={data chunks}`` - -:Description: Each object is split in **data-chunks** parts, - each stored on a different OSD. - -:Type: Integer -:Required: Yes. -:Example: 4 - -``m={coding-chunks}`` - -:Description: Compute **coding chunks** for each object and store them - on different OSDs. The number of coding chunks is also - the number of OSDs that can be down without losing data. - -:Type: Integer -:Required: Yes. -:Example: 2 - -``technique={reed_sol_van|reed_sol_r6_op|cauchy_orig|cauchy_good|liberation|blaum_roth|liber8tion}`` - -:Description: The more flexible technique is *reed_sol_van* : it is - enough to set *k* and *m*. The *cauchy_good* technique - can be faster but you need to chose the *packetsize* - carefully. All of *reed_sol_r6_op*, *liberation*, - *blaum_roth*, *liber8tion* are *RAID6* equivalents in - the sense that they can only be configured with *m=2*. - -:Type: String -:Required: No. -:Default: reed_sol_van - -``packetsize={bytes}`` - -:Description: The encoding will be done on packets of *bytes* size at - a time. Chosing the right packet size is difficult. The - *jerasure* documentation contains extensive information - on this topic. - -:Type: Integer -:Required: No. -:Default: 2048 - -``crush-root={root}`` - -:Description: The name of the crush bucket used for the first step of - the ruleset. For intance **step take default**. - -:Type: String -:Required: No. -:Default: default - -``crush-failure-domain={bucket-type}`` - -:Description: Ensure that no two chunks are in a bucket with the same - failure domain. For instance, if the failure domain is - **host** no two chunks will be stored on the same - host. It is used to create a ruleset step such as **step - chooseleaf host**. - -:Type: String -:Required: No. -:Default: host - -``crush-device-class={device-class}`` - -:Description: Restrict placement to devices of a specific class (e.g., - ``ssd`` or ``hdd``), using the crush device class names - in the CRUSH map. - -:Type: String -:Required: No. -:Default: - - ``directory={directory}`` - -:Description: Set the **directory** name from which the erasure code - plugin is loaded. - -:Type: String -:Required: No. -:Default: /usr/lib/ceph/erasure-code - -``--force`` - -:Description: Override an existing profile by the same name. - -:Type: String -:Required: No. - |