1 =======================
2 ISA erasure code plugin
3 =======================
5 The *isa* plugin encapsulates the `ISA
6 <https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version/>`_
7 library. It only runs on Intel processors.
12 To create a new *isa* erasure code profile::
14 ceph osd erasure-code-profile set {name} \
16 technique={reed_sol_van|cauchy} \
20 [crush-failure-domain={bucket-type}] \
21 [crush-device-class={device-class}] \
22 [directory={directory}] \
29 :Description: Each object is split in **data-chunks** parts,
30 each stored on a different OSD.
38 :Description: Compute **coding chunks** for each object and store them
39 on different OSDs. The number of coding chunks is also
40 the number of OSDs that can be down without losing data.
46 ``technique={reed_sol_van|cauchy}``
48 :Description: The ISA plugin comes in two `Reed Solomon
49 <https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction>`_
50 forms. If *reed_sol_van* is set, it is `Vandermonde
51 <https://en.wikipedia.org/wiki/Vandermonde_matrix>`_, if
52 *cauchy* is set, it is `Cauchy
53 <https://en.wikipedia.org/wiki/Cauchy_matrix>`_.
57 :Default: reed_sol_van
61 :Description: The name of the crush bucket used for the first step of
62 the CRUSH rule. For intance **step take default**.
68 ``crush-failure-domain={bucket-type}``
70 :Description: Ensure that no two chunks are in a bucket with the same
71 failure domain. For instance, if the failure domain is
72 **host** no two chunks will be stored on the same
73 host. It is used to create a CRUSH rule step such as **step
80 ``crush-device-class={device-class}``
82 :Description: Restrict placement to devices of a specific class (e.g.,
83 ``ssd`` or ``hdd``), using the crush device class names
90 ``directory={directory}``
92 :Description: Set the **directory** name from which the erasure code
97 :Default: /usr/lib/ceph/erasure-code
101 :Description: Override an existing profile by the same name.