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
orhdd
), 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.