The cinder.volume.drivers.dell_emc.sc.storagecenter_common Module

The cinder.volume.drivers.dell_emc.sc.storagecenter_common Module

class SCCommonDriver(*args, **kwargs)

Bases: cinder.volume.driver.ManageableVD, cinder.volume.driver.ManageableSnapshotsVD, cinder.volume.driver.BaseVD

check_for_setup_error()

Validates the configuration information.

create_cloned_volume(volume, src_vref)

Creates a clone of the specified volume.

create_export(context, volume, connector)

Create an export of a volume.

The volume exists on creation and will be visible on initialize connection. So nothing to do here.

create_group(context, group)

Creates a group.

Parameters:
  • context – the context of the caller.
  • group – the Group object of the group to be created.
Returns:

model_update

model_update will be in this format: {‘status’: xxx, ……}.

If the status in model_update is ‘error’, the manager will throw an exception and it will be caught in the try-except block in the manager. If the driver throws an exception, the manager will also catch it in the try-except block. The group status in the db will be changed to ‘error’.

For a successful operation, the driver can either build the model_update and return it or return None. The group status will be set to ‘available’.

create_group_from_src(context, group, volumes, group_snapshot=None, snapshots=None, source_group=None, source_vols=None)

Creates a group from source.

Parameters:
  • context – the context of the caller.
  • group – the Group object to be created.
  • volumes – a list of Volume objects in the group.
  • group_snapshot – the GroupSnapshot object as source.
  • snapshots – a list of Snapshot objects in group_snapshot.
  • source_group – the Group object as source.
  • source_vols – a list of Volume objects in the source_group.
Returns:

model_update, volumes_model_update

The source can be group_snapshot or a source_group.

param volumes is a list of objects retrieved from the db. It cannot be assigned to volumes_model_update. volumes_model_update is a list of dictionaries. It has to be built by the driver. An entry will be in this format: {‘id’: xxx, ‘status’: xxx, ……}. model_update will be in this format: {‘status’: xxx, ……}.

To be consistent with other volume operations, the manager will assume the operation is successful if no exception is thrown by the driver. For a successful operation, the driver can either build the model_update and volumes_model_update and return them or return None, None.

create_group_snapshot(context, group_snapshot, snapshots)

Creates a group_snapshot.

Parameters:
  • context – the context of the caller.
  • group_snapshot – the GroupSnapshot object to be created.
  • snapshots – a list of Snapshot objects in the group_snapshot.
Returns:

model_update, snapshots_model_update

param snapshots is a list of Snapshot objects. It cannot be assigned to snapshots_model_update. snapshots_model_update is a list of dictionaries. It has to be built by the driver. An entry will be in this format: {‘id’: xxx, ‘status’: xxx, ……}. model_update will be in this format: {‘status’: xxx, ……}.

The driver should populate snapshots_model_update and model_update and return them.

The manager will check snapshots_model_update and update db accordingly for each snapshot. If the driver successfully deleted some snapshots but failed to delete others, it should set statuses of the snapshots accordingly so that the manager can update db correctly.

If the status in any entry of snapshots_model_update is ‘error’, the status in model_update will be set to the same if it is not already ‘error’.

If the status in model_update is ‘error’, the manager will raise an exception and the status of group_snapshot will be set to ‘error’ in the db. If snapshots_model_update is not returned by the driver, the manager will set the status of every snapshot to ‘error’ in the except block.

If the driver raises an exception during the operation, it will be caught by the try-except block in the manager and the statuses of group_snapshot and all snapshots will be set to ‘error’.

For a successful operation, the driver can either build the model_update and snapshots_model_update and return them or return None, None. The statuses of group_snapshot and all snapshots will be set to ‘available’ at the end of the manager function.

create_snapshot(snapshot)

Create snapshot

create_volume(volume)

Create a volume.

create_volume_from_snapshot(volume, snapshot)

Create new volume from other volume’s snapshot on appliance.

delete_group(context, group, volumes)

Deletes a group.

Parameters:
  • context – the context of the caller.
  • group – the Group object of the group to be deleted.
  • volumes – a list of Volume objects in the group.
Returns:

model_update, volumes_model_update

param volumes is a list of objects retrieved from the db. It cannot be assigned to volumes_model_update. volumes_model_update is a list of dictionaries. It has to be built by the driver. An entry will be in this format: {‘id’: xxx, ‘status’: xxx, ……}. model_update will be in this format: {‘status’: xxx, ……}.

The driver should populate volumes_model_update and model_update and return them.

The manager will check volumes_model_update and update db accordingly for each volume. If the driver successfully deleted some volumes but failed to delete others, it should set statuses of the volumes accordingly so that the manager can update db correctly.

If the status in any entry of volumes_model_update is ‘error_deleting’ or ‘error’, the status in model_update will be set to the same if it is not already ‘error_deleting’ or ‘error’.

If the status in model_update is ‘error_deleting’ or ‘error’, the manager will raise an exception and the status of the group will be set to ‘error’ in the db. If volumes_model_update is not returned by the driver, the manager will set the status of every volume in the group to ‘error’ in the except block.

If the driver raises an exception during the operation, it will be caught by the try-except block in the manager. The statuses of the group and all volumes in it will be set to ‘error’.

For a successful operation, the driver can either build the model_update and volumes_model_update and return them or return None, None. The statuses of the group and all volumes will be set to ‘deleted’ after the manager deletes them from db.

delete_group_snapshot(context, group_snapshot, snapshots)

Deletes a group_snapshot.

Parameters:
  • context – the context of the caller.
  • group_snapshot – the GroupSnapshot object to be deleted.
  • snapshots – a list of Snapshot objects in the group_snapshot.
Returns:

model_update, snapshots_model_update

param snapshots is a list of objects. It cannot be assigned to snapshots_model_update. snapshots_model_update is a list of of dictionaries. It has to be built by the driver. An entry will be in this format: {‘id’: xxx, ‘status’: xxx, ……}. model_update will be in this format: {‘status’: xxx, ……}.

The driver should populate snapshots_model_update and model_update and return them.

The manager will check snapshots_model_update and update db accordingly for each snapshot. If the driver successfully deleted some snapshots but failed to delete others, it should set statuses of the snapshots accordingly so that the manager can update db correctly.

If the status in any entry of snapshots_model_update is ‘error_deleting’ or ‘error’, the status in model_update will be set to the same if it is not already ‘error_deleting’ or ‘error’.

If the status in model_update is ‘error_deleting’ or ‘error’, the manager will raise an exception and the status of group_snapshot will be set to ‘error’ in the db. If snapshots_model_update is not returned by the driver, the manager will set the status of every snapshot to ‘error’ in the except block.

If the driver raises an exception during the operation, it will be caught by the try-except block in the manager and the statuses of group_snapshot and all snapshots will be set to ‘error’.

For a successful operation, the driver can either build the model_update and snapshots_model_update and return them or return None, None. The statuses of group_snapshot and all snapshots will be set to ‘deleted’ after the manager deletes them from db.

delete_snapshot(snapshot)
delete_volume(volume)
do_setup(context)

One time driver setup.

Called once by the manager after the driver is loaded. Sets up clients, check licenses, sets up protocol specific helpers.

ensure_export(context, volume)

Ensure an export of a volume.

Per the eqlx driver we just make sure that the volume actually exists where we think it does.

extend_volume(volume, new_size)

Extend the size of the volume.

failback_volumes(volumes)

This is a generic volume failback.

Parameters:volumes – List of volumes that need to be failed back.
Returns:volume_updates for the list of volumes.
failover_host(context, volumes, secondary_id=None, groups=None)

Failover to secondary.

Parameters:
  • context – security context
  • secondary_id – Specifies rep target to fail over to
  • volumes – List of volumes serviced by this backend.
Returns:

destssn, volume_updates data structure

Example volume_updates data structure:


[{‘volume_id’: <cinder-uuid>,
‘updates’: {‘provider_id’: 8,
‘replication_status’: ‘failed-over’, ‘replication_extended_status’: ‘whatever’,…}},]
get_volume_stats(refresh=False)

Get volume status.

If ‘refresh’ is True, run update the stats first.

manage_existing(volume, existing_ref)

Brings an existing backend storage object under Cinder management.

existing_ref is passed straight through from the API request’s manage_existing_ref value, and it is up to the driver how this should be interpreted. It should be sufficient to identify a storage object that the driver should somehow associate with the newly-created cinder volume structure.

There are two ways to do this:

  1. Rename the backend storage object so that it matches the, volume[‘name’] which is how drivers traditionally map between a cinder volume and the associated backend storage object.
  2. Place some metadata on the volume, or somewhere in the backend, that allows other driver requests (e.g. delete, clone, attach, detach…) to locate the backend storage object when required.

If the existing_ref doesn’t make sense, or doesn’t refer to an existing backend storage object, raise a ManageExistingInvalidReference exception.

The volume may have a volume_type, and the driver can inspect that and compare against the properties of the referenced backend storage object. If they are incompatible, raise a ManageExistingVolumeTypeMismatch, specifying a reason for the failure.

Parameters:
  • volume – Cinder volume to manage
  • existing_ref – Driver-specific information used to identify a volume
manage_existing_get_size(volume, existing_ref)

Return size of volume to be managed by manage_existing.

When calculating the size, round up to the next GB.

Parameters:
  • volume – Cinder volume to manage
  • existing_ref – Driver-specific information used to identify a volume
manage_existing_snapshot(snapshot, existing_ref)

Brings an existing backend storage object under Cinder management.

existing_ref is passed straight through from the API request’s manage_existing_ref value, and it is up to the driver how this should be interpreted. It should be sufficient to identify a storage object that the driver should somehow associate with the newly-created cinder snapshot structure.

There are two ways to do this:

  1. Rename the backend storage object so that it matches the snapshot[‘name’] which is how drivers traditionally map between a cinder snapshot and the associated backend storage object.
  2. Place some metadata on the snapshot, or somewhere in the backend, that allows other driver requests (e.g. delete) to locate the backend storage object when required.

If the existing_ref doesn’t make sense, or doesn’t refer to an existing backend storage object, raise a ManageExistingInvalidReference exception.

manage_existing_snapshot_get_size(snapshot, existing_ref)

Return size of snapshot to be managed by manage_existing.

When calculating the size, round up to the next GB.

remove_export(context, volume)

Remove an export of a volume.

We do nothing here to match the nothing we do in create export. Again we do everything in initialize and terminate connection.

retype(ctxt, volume, new_type, diff, host)

Convert the volume to be of the new type.

Returns a boolean indicating whether the retype occurred.

Parameters:
  • ctxt – Context
  • volume – A dictionary describing the volume to migrate
  • new_type – A dictionary describing the volume type to convert to
  • diff – A dictionary with the difference between the two types
  • host – A dictionary describing the host to migrate to, where host[‘host’] is its name, and host[‘capabilities’] is a dictionary of its reported capabilities (Not Used).
Returns:

Boolean or Boolean, model_update tuple.

thaw_backend(context)

Notify the backend that it’s unfrozen/thawed.

This is a gate. We do not allow the backend to be thawed if it is still failed over.

Parameters:context – security context
Response:True on success
Raises:Invalid – if it cannot be thawed.
unmanage(volume)

Removes the specified volume from Cinder management.

Does not delete the underlying backend storage object.

For most drivers, this will not need to do anything. However, some drivers might use this call as an opportunity to clean up any Cinder-specific configuration that they have associated with the backend storage object.

Parameters:volume – Cinder volume to unmanage
unmanage_snapshot(snapshot)

Removes the specified snapshot from Cinder management.

Does not delete the underlying backend storage object.

NOTE: We do set the expire countdown to 1 day. Once a snapshot is
unmanaged it will expire 24 hours later.
update_group(context, group, add_volumes=None, remove_volumes=None)

Updates a group.

Parameters:
  • context – the context of the caller.
  • group – the Group object of the group to be updated.
  • add_volumes – a list of Volume objects to be added.
  • remove_volumes – a list of Volume objects to be removed.
Returns:

model_update, add_volumes_update, remove_volumes_update

model_update is a dictionary that the driver wants the manager to update upon a successful return. If None is returned, the manager will set the status to ‘available’.

add_volumes_update and remove_volumes_update are lists of dictionaries that the driver wants the manager to update upon a successful return. Note that each entry requires a {‘id’: xxx} so that the correct volume entry can be updated. If None is returned, the volume will remain its original status. Also note that you cannot directly assign add_volumes to add_volumes_update as add_volumes is a list of volume objects and cannot be used for db update directly. Same with remove_volumes.

If the driver throws an exception, the status of the group as well as those of the volumes to be added/removed will be set to ‘error’.

update_migrated_volume(ctxt, volume, new_volume, original_volume_status)

Return model update for migrated volume.

Parameters:
  • volume – The original volume that was migrated to this backend
  • new_volume – The migration volume object that was created on this backend as part of the migration process
  • original_volume_status – The status of the original volume
Returns:

model_update to update DB with any needed changes

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