Feature Overview (aka. Goal Summary)  

Allow LVMS users to remove a device from a deviceClass or  a complete deviceClasses.

Goals (aka. expected user outcomes)

User should be able to remove a disk device or a complete deviceClass, in case device is no longer needed, or was added accidentally. Currently, this is a cumbersome procedure requiring the complete removal of the LVMCLuster

Requirements (aka. Acceptance Criteria):

For device removal:

1. Remove an existing single device from a list of devices specified in a deviceClass. This needs to trigger the necessary actions on LVM level to remove / free this device from the volumegroup (pvmove / vgreduce).
2. The removal might take some time, if data needs to be moved to other devices, to free up the device to be removed. Status of the transfer/removal should be visible on the status field.
3. Removal might fail, if the remaining devices do not have enough capacity to hold all data.
4. Removal should be robust, e.g. if the node fails (power outage) during removal operation, no data should be lost. This is  handled by LVM , but needs to be considered during design and tested/verified during QE.

For deviceClass removal:

1. deviceClass can only be removed if the corresponding StorageClass has no PVC/PVs attached to it. Otherwise, removal will be rejected with a corresponding error message.

Questions to Answer (Optional):

n/a

Out of Scope

High-level list of items that are out of scope.  Initial completion during Refinement status.

Wiping disks after removal - removed disks will otherwise be untouched, in case there is data on non-lvm owned areas. 

Background

n/a

Customer Considerations

This has been asked for by customers, see linked RFEs

Documentation Considerations

Doc has existing statements that devices/deviceClasses can not be removed. This needs to be changed, and instructions on the requirements / procedures to do so need to be added (maybe in a "day2 operations" section).

Interoperability Considerations

none