ISA erasure code plugin¶

The isa plugin encapsulates the ISA library.

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 forms. If reed_sol_van is set, it is Vandermonde, if cauchy is set, it is Cauchy.
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 CRUSH rule. For instance 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 CRUSH rule 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.