[ceph.git] / ceph / doc / rados / operations / erasure-code-isa.rst

=======================
ISA erasure code plugin
=======================

The *isa* plugin encapsulates the `ISA
<https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version/>`_
library. It only runs on Intel processors.

Create an isa profile
=====================

To create a new *isa* erasure code profile::

        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 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.
Commit	Line	Data
7c673cae FG	1	=======================
	2	ISA erasure code plugin
	3	=======================
	4
	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.
	8
	9	Create an isa profile
	10	=====================
	11
	12	To create a new isa erasure code profile::
	13
	14	ceph osd erasure-code-profile set {name} \
	15	plugin=isa \
	16	technique={reed_sol_van\|cauchy} \
	17	[k={data-chunks}] \
	18	[m={coding-chunks}] \
224ce89b WB	19	[crush-root={root}] \
	20	[crush-failure-domain={bucket-type}] \
	21	[crush-device-class={device-class}] \
7c673cae FG	22	[directory={directory}] \
	23	[--force]
	24
	25	Where:
	26
	27	``k={data chunks}``
	28
	29	:Description: Each object is split in data-chunks parts,
	30	each stored on a different OSD.
	31
	32	:Type: Integer
	33	:Required: No.
	34	:Default: 7
	35
	36	``m={coding-chunks}``
	37
	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.
	41
	42	:Type: Integer
	43	:Required: No.
	44	:Default: 3
	45
	46	``technique={reed_sol_van\|cauchy}``
	47
	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>`_.
	54
	55	:Type: String
	56	:Required: No.
	57	:Default: reed_sol_van
	58
224ce89b	59	``crush-root={root}``
7c673cae FG	60
	61	:Description: The name of the crush bucket used for the first step of
	62	the ruleset. For intance step take default.
	63
	64	:Type: String
	65	:Required: No.
	66	:Default: default
	67
224ce89b	68	``crush-failure-domain={bucket-type}``
7c673cae FG	69
	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 ruleset step such as **step
	74	chooseleaf host**.
	75
	76	:Type: String
	77	:Required: No.
	78	:Default: host
	79
224ce89b WB	80	``crush-device-class={device-class}``
	81
	82	:Description: Restrict placement to devices of a specific class (e.g.,
	83	``ssd`` or ``hdd``), using the crush device class names
	84	in the CRUSH map.
	85
	86	:Type: String
	87	:Required: No.
	88	:Default:
	89
7c673cae FG	90	``directory={directory}``
	91
	92	:Description: Set the directory name from which the erasure code
	93	plugin is loaded.
	94
	95	:Type: String
	96	:Required: No.
	97	:Default: /usr/lib/ceph/erasure-code
	98
	99	``--force``
	100
	101	:Description: Override an existing profile by the same name.
	102
	103	:Type: String
	104	:Required: No.
	105