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diff --git a/src/ceph/doc/rados/operations/erasure-code-profile.rst b/src/ceph/doc/rados/operations/erasure-code-profile.rst deleted file mode 100644 index ddf772d..0000000 --- a/src/ceph/doc/rados/operations/erasure-code-profile.rst +++ /dev/null @@ -1,121 +0,0 @@ -===================== -Erasure code profiles -===================== - -Erasure code is defined by a **profile** and is used when creating an -erasure coded pool and the associated crush ruleset. - -The **default** erasure code profile (which is created when the Ceph -cluster is initialized) provides the same level of redundancy as two -copies but requires 25% less disk space. It is described as a profile -with **k=2** and **m=1**, meaning the information is spread over three -OSD (k+m == 3) and one of them can be lost. - -To improve redundancy without increasing raw storage requirements, a -new profile can be created. For instance, a profile with **k=10** and -**m=4** can sustain the loss of four (**m=4**) OSDs by distributing an -object on fourteen (k+m=14) OSDs. The object is first divided in -**10** chunks (if the object is 10MB, each chunk is 1MB) and **4** -coding chunks are computed, for recovery (each coding chunk has the -same size as the data chunk, i.e. 1MB). The raw space overhead is only -40% and the object will not be lost even if four OSDs break at the -same time. - -.. _list of available plugins: - -.. toctree:: - :maxdepth: 1 - - erasure-code-jerasure - erasure-code-isa - erasure-code-lrc - erasure-code-shec - -osd erasure-code-profile set -============================ - -To create a new erasure code profile:: - - ceph osd erasure-code-profile set {name} \ - [{directory=directory}] \ - [{plugin=plugin}] \ - [{stripe_unit=stripe_unit}] \ - [{key=value} ...] \ - [--force] - -Where: - -``{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 - -``{plugin=plugin}`` - -:Description: Use the erasure code **plugin** to compute coding chunks - and recover missing chunks. See the `list of available - plugins`_ for more information. - -:Type: String -:Required: No. -:Default: jerasure - -``{stripe_unit=stripe_unit}`` - -:Description: The amount of data in a data chunk, per stripe. For - example, a profile with 2 data chunks and stripe_unit=4K - would put the range 0-4K in chunk 0, 4K-8K in chunk 1, - then 8K-12K in chunk 0 again. This should be a multiple - of 4K for best performance. The default value is taken - from the monitor config option - ``osd_pool_erasure_code_stripe_unit`` when a pool is - created. The stripe_width of a pool using this profile - will be the number of data chunks multiplied by this - stripe_unit. - -:Type: String -:Required: No. - -``{key=value}`` - -:Description: The semantic of the remaining key/value pairs is defined - by the erasure code plugin. - -:Type: String -:Required: No. - -``--force`` - -:Description: Override an existing profile by the same name, and allow - setting a non-4K-aligned stripe_unit. - -:Type: String -:Required: No. - -osd erasure-code-profile rm -============================ - -To remove an erasure code profile:: - - ceph osd erasure-code-profile rm {name} - -If the profile is referenced by a pool, the deletion will fail. - -osd erasure-code-profile get -============================ - -To display an erasure code profile:: - - ceph osd erasure-code-profile get {name} - -osd erasure-code-profile ls -=========================== - -To list the names of all erasure code profiles:: - - ceph osd erasure-code-profile ls - |