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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.
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