ISA erasure code plugin¶
The isa plugin encapsulates the ISA 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 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 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 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.,
ssdorhdd), 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.
