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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:54:28 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:54:28 +0000
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Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+=======================
+ISA erasure code plugin
+=======================
+
+The *isa* plugin encapsulates the `ISA
+<https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version/>`_
+library.
+
+Create an isa profile
+=====================
+
+To create a new *isa* erasure code profile:
+
+.. prompt:: bash $
+
+ ceph osd erasure-code-profile set {name} \
+ plugin=isa \
+ technique={reed_sol_van|cauchy} \
+ [k={data-chunks}] \
+ [m={coding-chunks}] \
+ [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: No.
+:Default: 7
+
+``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: No.
+:Default: 3
+
+``technique={reed_sol_van|cauchy}``
+
+:Description: The ISA plugin comes in two `Reed Solomon
+ <https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction>`_
+ forms. If *reed_sol_van* is set, it is `Vandermonde
+ <https://en.wikipedia.org/wiki/Vandermonde_matrix>`_, if
+ *cauchy* is set, it is `Cauchy
+ <https://en.wikipedia.org/wiki/Cauchy_matrix>`_.
+
+:Type: String
+:Required: No.
+:Default: reed_sol_van
+
+``crush-root={root}``
+
+:Description: The name of the crush bucket used for the first step of
+ the CRUSH rule. For instance **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 CRUSH rule 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.
+