mirror of
https://github.com/ceph/ceph
synced 2024-12-20 18:33:44 +00:00
dc7a2aaf7a
1) ruleset is an obsolete term, and
2) crush-{rule,failure-domain,...} is more descriptive.
Note that we are changing the names of the erasure code profile keys
from ruleset-* to crush-*. We will update this on upgrade when the
luminous flag is set, but that means that during mon upgrade you cannot
create EC pools that use these fields.
When the upgrade completes (users sets require_osd_release = luminous)
existing ec profiles are updated automatically.
Signed-off-by: Sage Weil <sage@redhat.com>
106 lines
2.7 KiB
ReStructuredText
106 lines
2.7 KiB
ReStructuredText
=======================
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ISA erasure code plugin
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=======================
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The *isa* plugin 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 *isa* erasure code profile::
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ceph osd erasure-code-profile set {name} \
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plugin=isa \
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technique={reed_sol_van|cauchy} \
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[k={data-chunks}] \
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[m={coding-chunks}] \
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[crush-root={root}] \
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[crush-failure-domain={bucket-type}] \
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[crush-device-class={device-class}] \
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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: No.
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:Default: 7
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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: No.
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:Default: 3
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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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``crush-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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``crush-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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``crush-device-class={device-class}``
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:Description: Restrict placement to devices of a specific class (e.g.,
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``ssd`` or ``hdd``), using the crush device class names
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in the CRUSH map.
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:Type: String
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:Required: No.
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:Default:
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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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