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https://github.com/ceph/ceph
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95 lines
2.5 KiB
ReStructuredText
95 lines
2.5 KiB
ReStructuredText
=======================
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ISA erasure code plugin
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=======================
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The *isa* plugin is encapsulates the `ISA
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<https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version/>`_
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library. It only runs on Intel processors.
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Create an isa profile
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=====================
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To create a new *jerasure* erasure code profile::
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ceph osd erasure-code-profile set {name} \
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plugin=isa \
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k={data-chunks} \
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m={coding-chunks} \
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technique={reed_sol_van|cauchy} \
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[ruleset-root={root}] \
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[ruleset-failure-domain={bucket-type}] \
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[directory={directory}] \
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[--force]
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Where:
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``k={data chunks}``
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:Description: Each object is split in **data-chunks** parts,
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each stored on a different OSD.
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:Type: Integer
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:Required: Yes.
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:Example: 4
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``m={coding-chunks}``
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:Description: Compute **coding chunks** for each object and store them
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on different OSDs. The number of coding chunks is also
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the number of OSDs that can be down without losing data.
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:Type: Integer
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:Required: Yes.
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:Example: 2
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``technique={reed_sol_van|cauchy}``
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:Description: The ISA plugin comes in two `Reed Solomon
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<https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction>`_
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forms. If *reed_sol_van* is set, it is `Vandermonde
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<https://en.wikipedia.org/wiki/Vandermonde_matrix>`_, if
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*cauchy* is set, it is `Cauchy
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<https://en.wikipedia.org/wiki/Cauchy_matrix>`_.
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:Type: String
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:Required: No.
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:Default: reed_sol_van
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``ruleset-root={root}``
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:Description: The name of the crush bucket used for the first step of
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the ruleset. For intance **step take default**.
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:Type: String
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:Required: No.
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:Default: default
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``ruleset-failure-domain={bucket-type}``
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:Description: Ensure that no two chunks are in a bucket with the same
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failure domain. For instance, if the failure domain is
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**host** no two chunks will be stored on the same
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host. It is used to create a ruleset step such as **step
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chooseleaf host**.
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:Type: String
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:Required: No.
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:Default: host
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``directory={directory}``
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:Description: Set the **directory** name from which the erasure code
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plugin is loaded.
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:Type: String
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:Required: No.
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:Default: /usr/lib/ceph/erasure-code
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``--force``
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:Description: Override an existing profile by the same name.
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:Type: String
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:Required: No.
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