Librbd (Python)¶

The rbd python module provides file-like access to RBD images.

Example: Creating and writing to an image¶

To use rbd, you must first connect to RADOS and open an IO context:

cluster = rados.Rados(conffile='my_ceph.conf')
cluster.connect()
ioctx = cluster.open_ioctx('mypool')

Then you instantiate an :class:rbd.RBD object, which you use to create the image:

rbd_inst = rbd.RBD()
size = 4 * 1024**3  # 4 GiB
rbd_inst.create(ioctx, 'myimage', size)

To perform I/O on the image, you instantiate an :class:rbd.Image object:

image = rbd.Image(ioctx, 'myimage')
data = 'foo' * 200
image.write(data, 0)

This writes ‘foo’ to the first 600 bytes of the image. Note that data cannot be :type:unicode - Librbd does not know how to deal with characters wider than a :c:type:char.

In the end, you will want to close the image, the IO context and the connection to RADOS:

image.close()
ioctx.close()
cluster.shutdown()

To be safe, each of these calls would need to be in a separate :finally block:

cluster = rados.Rados(conffile='my_ceph_conf')
try:
    cluster.connect()
    ioctx = cluster.open_ioctx('my_pool')
    try:
        rbd_inst = rbd.RBD()
        size = 4 * 1024**3  # 4 GiB
        rbd_inst.create(ioctx, 'myimage', size)
        image = rbd.Image(ioctx, 'myimage')
        try:
            data = 'foo' * 200
            image.write(data, 0)
        finally:
            image.close()
    finally:
        ioctx.close()
finally:
    cluster.shutdown()

This can be cumbersome, so the Rados, Ioctx, and Image classes can be used as context managers that close/shutdown automatically (see PEP 343). Using them as context managers, the above example becomes:

with rados.Rados(conffile='my_ceph.conf') as cluster:
    with cluster.open_ioctx('mypool') as ioctx:
        rbd_inst = rbd.RBD()
        size = 4 * 1024**3  # 4 GiB
        rbd_inst.create(ioctx, 'myimage', size)
        with rbd.Image(ioctx, 'myimage') as image:
            data = 'foo' * 200
            image.write(data, 0)

API Reference¶

This module is a thin wrapper around librbd.

It currently provides all the synchronous methods of librbd that do not use callbacks.

Error codes from librbd are turned into exceptions that subclass Error. Almost all methods may raise Error (the base class of all rbd exceptions), PermissionError and IOError, in addition to those documented for the method.

class rbd.RBD¶

This class wraps librbd CRUD functions.

clone(self, p_ioctx, p_name, p_snapname, c_ioctx, c_name, features=None, order=None, stripe_unit=None, stripe_count=None, data_pool=None)¶

Clone a parent rbd snapshot into a COW sparse child.

Parameters

p_ioctx – the parent context that represents the parent snap
p_name – the parent image name
p_snapname – the parent image snapshot name
c_ioctx – the child context that represents the new clone
c_name – the clone (child) name
features (int) – bitmask of features to enable; if set, must include layering
order (int) – the image is split into (2**order) byte objects
stripe_unit (int) – stripe unit in bytes (default None to let librbd decide)
stripe_count (int) – objects to stripe over before looping
data_pool (str) – optional separate pool for data blocks

Raises

TypeError

Raises

InvalidArgument

Raises

ImageExists

Raises

FunctionNotSupported

Raises

ArgumentOutOfRange

config_get(self, ioctx, key)¶

Get a pool-level configuration override.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is read
key (str) – key

Returns

str - value

config_list(self, ioctx)¶

List pool-level config overrides.

Returns: ConfigPoolIterator

config_remove(self, ioctx, key)¶

Remove a pool-level configuration override.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is read
key (str) – key

Returns

str - value

config_set(self, ioctx, key, value)¶

Get a pool-level configuration override.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is read
key (str) – key
value (str) – value

create(self, ioctx, name, size, order=None, old_format=True, features=None, stripe_unit=None, stripe_count=None, data_pool=None)¶

Create an rbd image.

Parameters

ioctx (rados.Ioctx) – the context in which to create the image
name (str) – what the image is called
size (int) – how big the image is in bytes
order (int) – the image is split into (2**order) byte objects
old_format (bool) – whether to create an old-style image that is accessible by old clients, but can’t use more advanced features like layering.
features (int) – bitmask of features to enable
stripe_unit (int) – stripe unit in bytes (default None to let librbd decide)
stripe_count (int) – objects to stripe over before looping
data_pool (str) – optional separate pool for data blocks

Raises

ImageExists

Raises

TypeError

Raises

InvalidArgument

Raises

FunctionNotSupported

features_from_string(self, str_features)¶

Get features bitmask from str, if str_features is empty, it will return RBD_FEATURES_DEFAULT.

Parameters: str_features (str) – feature str
Returns: int - the features bitmask of the image
Raises: InvalidArgument

features_to_string(self, features)¶

Convert features bitmask to str.

Parameters: features (int) – feature bitmask
Returns: str - the features str of the image
Raises: InvalidArgument

group_create(self, ioctx, name)¶

Create a group.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is used
name (str) – the name of the group

Raises

ObjectExists

Raises

InvalidArgument

Raises

FunctionNotSupported

group_list(self, ioctx)¶

List groups.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is read
Returns: list – a list of groups names
Raises: FunctionNotSupported

group_remove(self, ioctx, name)¶

Delete an RBD group. This may take a long time, since it does not return until every image in the group has been removed from the group.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the group is in
name (str) – the name of the group to remove

Raises

ObjectNotFound

Raises

InvalidArgument

Raises

FunctionNotSupported

group_rename(self, ioctx, src, dest)¶

Rename an RBD group.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the group is in
src (str) – the current name of the group
dest (str) – the new name of the group

Raises

ObjectExists

Raises

ObjectNotFound

Raises

InvalidArgument

Raises

FunctionNotSupported

list(self, ioctx)¶

List image names.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is read
Returns: list – a list of image names

list2(self, ioctx)¶

Iterate over the images in the pool.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool the image is in
Returns: ImageIterator

migration_abort(self, ioctx, image_name, on_progress=None)¶

Cancel a previously started but interrupted migration.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_name (str) – the name of the image
on_progress (callback function) – optional progress callback function

Raises

ImageNotFound

migration_commit(self, ioctx, image_name, on_progress=None)¶

Commit an executed RBD image migration.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_name (str) – the name of the image
on_progress (callback function) – optional progress callback function

Raises

ImageNotFound

migration_execute(self, ioctx, image_name, on_progress=None)¶

Execute a prepared RBD image migration.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_name (str) – the name of the image
on_progress (callback function) – optional progress callback function

Raises

ImageNotFound

migration_prepare(self, ioctx, image_name, dest_ioctx, dest_image_name, features=None, order=None, stripe_unit=None, stripe_count=None, data_pool=None)¶

Prepare an RBD image migration.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_name – the current name of the image
dest_ioctx (rados.Ioctx) – determines which pool to migration into
dest_image_name (str) – the name of the destination image (may be the same image)
features (int) – bitmask of features to enable; if set, must include layering
order (int) – the image is split into (2**order) byte objects
stripe_unit (int) – stripe unit in bytes (default None to let librbd decide)
stripe_count (int) – objects to stripe over before looping
data_pool (str) – optional separate pool for data blocks

Raises

TypeError

Raises

InvalidArgument

Raises

ImageExists

Raises

FunctionNotSupported

Raises

ArgumentOutOfRange

migration_status(self, ioctx, image_name)¶

Return RBD image migration status.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_name (str) – the name of the image

Returns

dict - contains the following keys:

source_pool_id (int) - source image pool id
source_pool_namespace (str) - source image pool namespace
source_image_name (str) - source image name
source_image_id (str) - source image id
dest_pool_id (int) - destination image pool id
dest_pool_namespace (str) - destination image pool namespace
dest_image_name (str) - destination image name
dest_image_id (str) - destination image id
state (int) - current migration state
state_description (str) - migration state description

Raises

ImageNotFound

mirror_image_instance_id_list(self, ioctx)¶

Iterate over the mirror image instance ids of a pool.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is read
Returns: MirrorImageInstanceIdIterator

mirror_image_status_list(self, ioctx)¶

Iterate over the mirror image statuses of a pool.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is read
Returns: MirrorImageStatusIterator

mirror_image_status_summary(self, ioctx)¶

Get mirror image status summary of a pool.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is read
Returns: list - a list of (state, count) tuples

mirror_mode_get(self, ioctx)¶

Get pool mirror mode.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is read
Returns: int - pool mirror mode

mirror_mode_set(self, ioctx, mirror_mode)¶

Set pool mirror mode.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is written
mirror_mode (int) – mirror mode to set

mirror_peer_add(self, ioctx, site_name, client_name, direction=RBD_MIRROR_PEER_DIRECTION_RX_TX)¶

Add mirror peer.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is used
site_name (str) – mirror peer site name
client_name (str) – mirror peer client name
direction (int) – the direction of the mirroring

Returns

str - peer uuid

mirror_peer_bootstrap_create(self, ioctx)¶

Creates a new RBD mirroring bootstrap token for an external cluster.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is written
Returns: str - bootstrap token

mirror_peer_bootstrap_import(self, ioctx, direction, token)¶

Import a bootstrap token from an external cluster to auto-configure the mirror peer.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is written
direction (int) – mirror peer direction
token (str) – bootstrap token

mirror_peer_get_attributes(self, ioctx, uuid)¶

Get optional mirror peer attributes

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is written
uuid (str) – uuid of the mirror peer

Returns

dict - contains the following keys:

mon_host (str) - monitor addresses
key (str) - CephX key

mirror_peer_list(self, ioctx)¶

Iterate over the peers of a pool.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool is read
Returns: MirrorPeerIterator

mirror_peer_remove(self, ioctx, uuid)¶

Remove mirror peer.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is used
uuid (str) – peer uuid

mirror_peer_set_attributes(self, ioctx, uuid, attributes)¶

Set optional mirror peer attributes

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is written
uuid (str) – uuid of the mirror peer
attributes (dict) – ‘mon_host’ and ‘key’ attributes

mirror_peer_set_client(self, ioctx, uuid, client_name)¶

Set mirror peer client name

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is written
uuid (str) – uuid of the mirror peer
client_name (str) – client name of the mirror peer to set

mirror_peer_set_cluster(self, ioctx, uuid, cluster_name)¶

mirror_peer_set_name(self, ioctx, uuid, site_name)¶

Set mirror peer site name

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is written
uuid (str) – uuid of the mirror peer
site_name (str) – site name of the mirror peer to set

mirror_site_name_get(self, rados)¶

Get the local cluster’s friendly site name

Parameters: rados – cluster connection
Returns: str - local site name

mirror_site_name_set(self, rados, site_name)¶

Set the local cluster’s friendly site name

Parameters

rados – cluster connection
site_name – friendly site name

namespace_create(self, ioctx, name)¶

Create an RBD namespace within a pool

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool
name (str) – namespace name

namespace_exists(self, ioctx, name)¶

Verifies if a namespace exists within a pool

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool
name (str) – namespace name

Returns

bool - true if namespace exists

namespace_list(self, ioctx)¶

List all namespaces within a pool

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool
Returns: list - collection of namespace names

namespace_remove(self, ioctx, name)¶

Remove an RBD namespace from a pool

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool
name (str) – namespace name

pool_init(self, ioctx, force)¶: Initialize an RBD pool :param ioctx: determines which RADOS pool :type ioctx: rados.Ioctx :param force: force init :type force: bool

pool_metadata_get(self, ioctx, key)¶

Get pool metadata for the given key.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is read
key (str) – metadata key

Returns

str - metadata value

pool_metadata_list(self, ioctx)¶

List pool metadata.

Returns: PoolMetadataIterator

pool_metadata_remove(self, ioctx, key)¶

Remove pool metadata for the given key.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is read
key (str) – metadata key

Returns

str - metadata value

pool_metadata_set(self, ioctx, key, value)¶

Set pool metadata for the given key.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool is read
key (str) – metadata key
value (str) – metadata value

pool_stats_get(self, ioctx)¶

Return RBD pool stats

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool

Returns

dict - contains the following keys:

image_count (int) - image count
image_provisioned_bytes (int) - image total HEAD provisioned bytes
image_max_provisioned_bytes (int) - image total max provisioned bytes
image_snap_count (int) - image snap count
trash_count (int) - trash image count
trash_provisioned_bytes (int) - trash total HEAD provisioned bytes
trash_max_provisioned_bytes (int) - trash total max provisioned bytes
trash_snap_count (int) - trash snap count

remove(self, ioctx, name, on_progress=None)¶

Delete an RBD image. This may take a long time, since it does not return until every object that comprises the image has been deleted. Note that all snapshots must be deleted before the image can be removed. If there are snapshots left, ImageHasSnapshots is raised. If the image is still open, or the watch from a crashed client has not expired, ImageBusy is raised.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
name (str) – the name of the image to remove
on_progress (callback function) – optional progress callback function

Raises

ImageNotFound, ImageBusy, ImageHasSnapshots

rename(self, ioctx, src, dest)¶

Rename an RBD image.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
src (str) – the current name of the image
dest (str) – the new name of the image

Raises

ImageNotFound, ImageExists

trash_get(self, ioctx, image_id)¶

Retrieve RBD image info from trash.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_id (str) – the id of the image to restore

Returns

dict - contains the following keys:

id (str) - image id
name (str) - image name
source (str) - source of deletion
deletion_time (datetime) - time of deletion
deferment_end_time (datetime) - time that an image is allowed to be removed from trash

Raises

ImageNotFound

trash_list(self, ioctx)¶

List all entries from trash.

Parameters: ioctx (rados.Ioctx) – determines which RADOS pool the image is in
Returns: TrashIterator

trash_move(self, ioctx, name, delay=0)¶

Move an RBD image to the trash.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
name (str) – the name of the image to remove
delay (int) – time delay in seconds before the image can be deleted from trash

Raises

ImageNotFound

trash_purge(self, ioctx, expire_ts=None, threshold=-1)¶

Delete RBD images from trash in bulk.

By default it removes images with deferment end time less than now.

The timestamp is configurable, e.g. delete images that have expired a week ago.

If the threshold is used it deletes images until X% pool usage is met.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
expire_ts (datetime) – timestamp for images to be considered as expired (UTC)
threshold (float) – percentage of pool usage to be met (0 to 1)

trash_remove(self, ioctx, image_id, force=False, on_progress=None)¶

Delete an RBD image from trash. If image deferment time has not expired PermissionError is raised.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_id (str) – the id of the image to remove
force (bool) – force remove even if deferment time has not expired
on_progress (callback function) – optional progress callback function

Raises

ImageNotFound, PermissionError

trash_restore(self, ioctx, image_id, name)¶

Restore an RBD image from trash.

Parameters

ioctx (rados.Ioctx) – determines which RADOS pool the image is in
image_id (str) – the id of the image to restore
name (str) – the new name of the restored image

Raises

ImageNotFound

version(self)¶

Get the version number of the librbd C library.

Returns: a tuple of (major, minor, extra) components of the librbd version

class rbd.Image(ioctx, name=None, snapshot=None, read_only=False, image_id=None)¶

This class represents an RBD image. It is used to perform I/O on the image and interact with snapshots.

Note: Any method of this class may raise ImageNotFound if the image has been deleted.

access_timestamp(self)¶: Return the access timestamp for the image.

aio_discard(self, offset, length, oncomplete)¶: Asynchronously trim the range from the image. It will be logically filled with zeroes.

aio_flush(self, oncomplete)¶: Asynchronously wait until all writes are fully flushed if caching is enabled.

aio_read(self, offset, length, oncomplete, fadvise_flags=0)¶

Asynchronously read data from the image

Raises InvalidArgument if part of the range specified is outside the image.

oncomplete will be called with the returned read value as well as the completion:

oncomplete(completion, data_read)

Parameters

offset (int) – the offset to start reading at
length (int) – how many bytes to read
oncomplete (completion) – what to do when the read is complete
fadvise_flags (int) – fadvise flags for this read

Returns

Completion - the completion object

Raises

InvalidArgument, IOError

aio_write(self, data, offset, oncomplete, fadvise_flags=0)¶

Asynchronously write data to the image

Raises InvalidArgument if part of the write would fall outside the image.

oncomplete will be called with the completion:

oncomplete(completion)

Parameters

data (bytes) – the data to be written
offset (int) – the offset to start writing at
oncomplete (completion) – what to do when the write is complete
fadvise_flags (int) – fadvise flags for this write

Returns

Completion - the completion object

Raises

InvalidArgument, IOError

block_name_prefix(self)¶

Get the RBD block name prefix

Returns: str - block name prefix

break_lock(self, client, cookie)¶: Release a lock held by another rados client.

close(self)¶

Release the resources used by this image object.

After this is called, this object should not be used.

config_get(self, key)¶

Get an image-level configuration override.

Parameters: key (str) – key
Returns: str - value

config_list(self)¶

List image-level config overrides.

Returns: ConfigImageIterator

config_remove(self, key)¶

Remove an image-level configuration override.

Parameters: key (str) – key

config_set(self, key, value)¶

Set an image-level configuration override.

Parameters

key (str) – key
value (str) – value

copy(self, dest_ioctx, dest_name, features=None, order=None, stripe_unit=None, stripe_count=None, data_pool=None)¶

Copy the image to another location.

Parameters

dest_ioctx (rados.Ioctx) – determines which pool to copy into
dest_name (str) – the name of the copy
features (int) – bitmask of features to enable; if set, must include layering
order (int) – the image is split into (2**order) byte objects
stripe_unit (int) – stripe unit in bytes (default None to let librbd decide)
stripe_count (int) – objects to stripe over before looping
data_pool (str) – optional separate pool for data blocks

Raises

TypeError

Raises

InvalidArgument

Raises

ImageExists

Raises

FunctionNotSupported

Raises

ArgumentOutOfRange

create_snap(self, name)¶

Create a snapshot of the image.

Parameters: name (str) – the name of the snapshot
Raises: ImageExists

create_timestamp(self)¶: Return the create timestamp for the image.

data_pool_id(self)¶

Get the pool id of the pool where the data of this RBD image is stored.

Returns: int - the pool id

deep_copy(self, dest_ioctx, dest_name, features=None, order=None, stripe_unit=None, stripe_count=None, data_pool=None)¶

Deep copy the image to another location.

Parameters

dest_ioctx (rados.Ioctx) – determines which pool to copy into
dest_name (str) – the name of the copy
features (int) – bitmask of features to enable; if set, must include layering
order (int) – the image is split into (2**order) byte objects
stripe_unit (int) – stripe unit in bytes (default None to let librbd decide)
stripe_count (int) – objects to stripe over before looping
data_pool (str) – optional separate pool for data blocks

Raises

TypeError

Raises

InvalidArgument

Raises

ImageExists

Raises

FunctionNotSupported

Raises

ArgumentOutOfRange

diff_iterate(self, offset, length, from_snapshot, iterate_cb, include_parent=True, whole_object=False)¶

Iterate over the changed extents of an image.

This will call iterate_cb with three arguments:

(offset, length, exists)

where the changed extent starts at offset bytes, continues for length bytes, and is full of data (if exists is True) or zeroes (if exists is False).

If from_snapshot is None, it is interpreted as the beginning of time and this generates all allocated extents.

The end version is whatever is currently selected (via set_snap) for the image.

iterate_cb may raise an exception, which will abort the diff and will be propagated to the caller.

Raises InvalidArgument if from_snapshot is after the currently set snapshot.

Raises ImageNotFound if from_snapshot is not the name of a snapshot of the image.

Parameters

offset (int) – start offset in bytes
length (int) – size of region to report on, in bytes
from_snapshot (str or None) – starting snapshot name, or None
iterate_cb (function acception arguments for offset, length, and exists) – function to call for each extent
include_parent (bool) – True if full history diff should include parent
whole_object (bool) – True if diff extents should cover whole object

Raises

InvalidArgument, IOError, ImageNotFound

discard(self, offset, length)¶: Trim the range from the image. It will be logically filled with zeroes.

features(self)¶

Get the features bitmask of the image.

Returns: int - the features bitmask of the image

flags(self)¶

Get the flags bitmask of the image.

Returns: int - the flags bitmask of the image

flatten(self, on_progress=None)¶: Flatten clone image (copy all blocks from parent to child) :param on_progress: optional progress callback function :type on_progress: callback function

flush(self)¶: Block until all writes are fully flushed if caching is enabled.

get_name(self)¶

Get the RBD image name

Returns: str - image name

get_parent_image_spec(self)¶

Get spec of the cloned image’s parent

Returns: dict - contains the following keys: * pool_name (str) - parent pool name * pool_namespace (str) - parent pool namespace * image_name (str) - parent image name * snap_name (str) - parent snapshot name
Raises: ImageNotFound if the image doesn’t have a parent

get_snap_limit(self)¶

Get the snapshot limit for an image.

Returns: int - the snapshot limit for an image

get_snap_timestamp(self, snap_id)¶: Get the snapshot timestamp for an image. :param snap_id: the snapshot id of a snap shot :returns: datetime - the snapshot timestamp for an image

group(self)¶

Get information about the image’s group.

Returns

dict - contains the following keys:

pool (int) - id of the group pool
name (str) - name of the group

id(self)¶

Get the RBD v2 internal image id

Returns: str - image id

invalidate_cache(self)¶: Drop any cached data for the image.

is_exclusive_lock_owner(self)¶

Get the status of the image exclusive lock.

Returns: bool - true if the image is exclusively locked

is_protected_snap(self, name)¶

Find out whether a snapshot is protected from deletion.

Parameters: name (str) – the snapshot to check
Returns: bool - whether the snapshot is protected
Raises: IOError, ImageNotFound

list_children(self)¶

List children of the currently set snapshot (set via set_snap()).

Returns: list - a list of (pool name, image name) tuples

list_children2(self)¶

Iterate over the children of the image or its snapshot.

Returns: ChildIterator

list_descendants(self)¶

Iterate over the descendants of the image.

Returns: ChildIterator

list_lockers(self)¶

List clients that have locked the image and information about the lock.

Returns

dict - contains the following keys:

tag - the tag associated with the lock (every additional locker must use the same tag)
exclusive - boolean indicating whether the
lock is exclusive or shared
lockers - a list of (client, cookie, address) tuples

list_snaps(self)¶

Iterate over the snapshots of an image.

Returns: SnapIterator

lock_acquire(self, lock_mode)¶

Acquire a managed lock on the image.

Parameters: lock_mode (int) – lock mode to set
Raises: ImageBusy if the lock could not be acquired

lock_break(self, lock_mode, lock_owner)¶

Break the image lock held by a another client.

Parameters: lock_owner (str) – the owner of the lock to break

lock_exclusive(self, cookie)¶

Take an exclusive lock on the image.

Raises: ImageBusy if a different client or cookie locked it ImageExists if the same client and cookie locked it

lock_get_owners(self)¶

Iterate over the lock owners of an image.

Returns: LockOwnerIterator

lock_release(self)¶: Release a managed lock on the image that was previously acquired.

lock_shared(self, cookie, tag)¶

Take a shared lock on the image. The tag must match that of the existing lockers, if any.

Raises: ImageBusy if a different client or cookie locked it ImageExists if the same client and cookie locked it

metadata_get(self, key)¶

Get image metadata for the given key.

Parameters: key (str) – metadata key
Returns: str - metadata value

metadata_list(self)¶

List image metadata.

Returns: MetadataIterator

metadata_remove(self, key)¶

Remove image metadata for the given key.

Parameters: key (str) – metadata key

metadata_set(self, key, value)¶

Set image metadata for the given key.

Parameters

key (str) – metadata key
value (str) – metadata value

mirror_image_demote(self)¶: Demote the image to secondary for mirroring.

mirror_image_disable(self, force)¶

Disable mirroring for the image.

Parameters: force (bool) – force disabling

mirror_image_enable(self)¶: Enable mirroring for the image.

mirror_image_get_info(self)¶

Get mirror info for the image.

Returns

dict - contains the following keys:

global_id (str) - image global id
state (int) - mirror state
primary (bool) - is image primary

mirror_image_get_instance_id(self)¶

Get mirror instance id for the image.

Returns: str - instance id

mirror_image_get_status(self)¶

Get mirror status for the image.

Returns

dict - contains the following keys:

name (str) - mirror image name
id (str) - mirror image id
info (dict) - mirror image info
state (int) - status mirror state
description (str) - status description
last_update (datetime) - last status update time
up (bool) - is mirroring agent up
remote_statuses (array) -
fsid (str) - remote fsid
state (int) - status mirror state
description (str) - status description
last_update (datetime) - last status update time
up (bool) - is mirroring agent up

mirror_image_promote(self, force)¶

Promote the image to primary for mirroring.

Parameters: force (bool) – force promoting

mirror_image_resync(self)¶: Flag the image to resync.

modify_timestamp(self)¶: Return the modify timestamp for the image.

old_format(self)¶

Find out whether the image uses the old RBD format.

Returns: bool - whether the image uses the old RBD format

op_features(self)¶

Get the op features bitmask of the image.

Returns: int - the op features bitmask of the image

overlap(self)¶

Get the number of overlapping bytes between the image and its parent image. If open to a snapshot, returns the overlap between the snapshot and the parent image.

Returns: int - the overlap in bytes
Raises: ImageNotFound if the image doesn’t have a parent

parent_id(self)¶

Get image id of a cloned image’s parent (if any)

Returns: str - the parent id
Raises: ImageNotFound if the image doesn’t have a parent

parent_info(self)¶

Deprecated. Use get_parent_image_spec instead.

Get information about a cloned image’s parent (if any)

Returns: tuple - (pool name, image name, snapshot name) components of the parent image
Raises: ImageNotFound if the image doesn’t have a parent

protect_snap(self, name)¶

Mark a snapshot as protected. This means it can’t be deleted until it is unprotected.

Parameters: name (str) – the snapshot to protect
Raises: IOError, ImageNotFound

read(self, offset, length, fadvise_flags=0)¶

Read data from the image. Raises InvalidArgument if part of the range specified is outside the image.

Parameters

offset (int) – the offset to start reading at
length (int) – how many bytes to read
fadvise_flags (int) – fadvise flags for this read

Returns

str - the data read

Raises

InvalidArgument, IOError

rebuild_object_map(self)¶: Rebuild the object map for the image HEAD or currently set snapshot

remove_snap(self, name)¶

Delete a snapshot of the image.

Parameters: name (str) – the name of the snapshot
Raises: IOError, ImageBusy, ImageNotFound

remove_snap2(self, name, flags)¶

Delete a snapshot of the image.

Parameters

name (str) – the name of the snapshot
flags – the flags for removal

Raises

IOError, ImageBusy

remove_snap_by_id(self, snap_id)¶

Delete a snapshot of the image by its id.

Parameters: id – the id of the snapshot
Raises: IOError, ImageBusy

remove_snap_limit(self)¶: Remove the snapshot limit for an image, essentially setting the limit to the maximum size allowed by the implementation.

rename_snap(self, srcname, dstname)¶

rename a snapshot of the image.

Parameters

srcname (str) – the src name of the snapshot
dstname (str) – the dst name of the snapshot

Raises

ImageExists

resize(self, size, allow_shrink=True)¶

Change the size of the image, allow shrink.

Parameters

size (int) – the new size of the image
allow_shrink (bool) – permit shrinking

rollback_to_snap(self, name)¶

Revert the image to its contents at a snapshot. This is a potentially expensive operation, since it rolls back each object individually.

Parameters: name (str) – the snapshot to rollback to
Raises: IOError

set_snap(self, name)¶

Set the snapshot to read from. Writes will raise ReadOnlyImage while a snapshot is set. Pass None to unset the snapshot (reads come from the current image) , and allow writing again.

Parameters: name (str or None) – the snapshot to read from, or None to unset the snapshot

set_snap_by_id(self, snap_id)¶

Set the snapshot to read from. Writes will raise ReadOnlyImage while a snapshot is set. Pass None to unset the snapshot (reads come from the current image) , and allow writing again.

Parameters: snap_id (int) – the snapshot to read from, or None to unset the snapshot

set_snap_limit(self, limit)¶

Set the snapshot limit for an image.

Parameters: limit – the new limit to set

size(self)¶

Get the size of the image. If open to a snapshot, returns the size of that snapshot.

Returns: int - the size of the image in bytes

snap_get_group_namespace(self, snap_id)¶

get the group namespace details. :param snap_id: the snapshot id of the group snapshot :type key: int :returns: dict - contains the following keys:

pool (int) - pool id

name (str) - group name

snap_name (str) - group snap name

snap_get_id(self, snap_name)¶

Get snapshot id by name.

Parameters: snap_name (str) – the snapshot name
Returns: int - snapshot id
Raises: ImageNotFound

snap_get_name(self, snap_id)¶

Get snapshot name by id.

Parameters: snap_id (int) – the snapshot id
Returns: str - snapshot name
Raises: ImageNotFound

snap_get_namespace_type(self, snap_id)¶: Get the snapshot namespace type. :param snap_id: the snapshot id of a snap shot :type key: int

snap_get_trash_namespace(self, snap_id)¶

get the trash namespace details. :param snap_id: the snapshot id of the trash snapshot :type key: int :returns: dict - contains the following keys:

original_name (str) - original snap name

sparsify(self, sparse_size)¶: Reclaim space for zeroed image extents

stat(self)¶

Get information about the image. Currently parent pool and parent name are always -1 and ‘’.

Returns

dict - contains the following keys:

size (int) - the size of the image in bytes
obj_size (int) - the size of each object that comprises the image
num_objs (int) - the number of objects in the image
order (int) - log_2(object_size)
block_name_prefix (str) - the prefix of the RADOS objects used to store the image
parent_pool (int) - deprecated
parent_name (str) - deprecated