======================================================================== Addressing discrepancies in reported volume sizes for EqualLogic storage ======================================================================== Problem ~~~~~~~ There is a discrepancy between both the actual volume size in EqualLogic (EQL) storage and the image size in the Image service, with what is reported to OpenStack database. This could lead to confusion if a user is creating volumes from an image that was uploaded from an EQL volume (through the Image service). The image size is slightly larger than the target volume size; this is because EQL size reporting accounts for additional storage used by EQL for internal volume metadata. To reproduce the issue follow the steps in the following procedure. This procedure assumes that the EQL array is provisioned, and that appropriate configuration settings have been included in ``/etc/cinder/cinder.conf`` to connect to the EQL array. Create a new volume. Note the ID and size of the volume. In the following example, the ID and size are ``74cf9c04-4543-47ae-a937-a9b7c6c921e7`` and ``1``, respectively: .. code-block:: console $ openstack volume create volume1 --size 1 +---------------------+--------------------------------------+ | Field | Value | +---------------------+--------------------------------------+ | attachments | [] | | availability_zone | nova | | bootable | false | | consistencygroup_id | None | | created_at | 2016-12-06T11:33:30.957318 | | description | None | | encrypted | False | | id | 74cf9c04-4543-47ae-a937-a9b7c6c921e7 | | migration_status | None | | multiattach | False | | name | volume1 | | properties | | | replication_status | disabled | | size | 1 | | snapshot_id | None | | source_volid | None | | status | creating | | type | iscsi | | updated_at | None | | user_id | c36cec73b0e44876a4478b1e6cd749bb | +---------------------+--------------------------------------+ Verify the volume size on the EQL array by using its command-line interface. The actual size (``VolReserve``) is 1.01GB. The EQL Group Manager should also report a volume size of 1.01GB: .. code-block:: console eql> volume select volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7 eql (volume_volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7)> show _______________________________ Volume Information ________________________________ Name: volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7 Size: 1GB VolReserve: 1.01GB VolReservelnUse: 0MB ReplReservelnUse: 0MB iSCSI Alias: volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7 iSCSI Name: iqn.2001-05.com.equallogic:0-8a0906-19f91850c-067000000b4532cl-volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7 ActualMembers: 1 Snap-Warn: 10% Snap-Depletion: delete-oldest Description: Snap-Reserve: 100% Snap-Reserve-Avail: 100% (1.01GB) Permission: read-write DesiredStatus: online Status: online Connections: O Snapshots: O Bind: Type: not-replicated ReplicationReserveSpace: 0MB Create a new image from this volume: .. code-block:: console $ openstack image create --volume volume1 \ --disk-format raw --container-format bare image_from_volume1 +---------------------+--------------------------------------+ | Field | Value | +---------------------+--------------------------------------+ | container_format | bare | | disk_format | raw | | display_description | None | | id | 850fd393-a968-4259-9c65-6b495cba5209 | | image_id | 3020a21d-ba37-4495-8899-07fc201161b9 | | image_name | image_from_volume1 | | is_public | False | | protected | False | | size | 1 | | status | uploading | | updated_at | 2016-12-05T12:43:56.000000 | | volume_type | iscsi | +---------------------+--------------------------------------+ When you uploaded the volume in the previous step, the Image service reported the volume's size as ``1`` (GB). However, when using :command:`openstack image show` to show the image, the displayed size is 1085276160 bytes, or roughly 1.01 GB: +------------------+--------------------------------------+ | Property | Value | +------------------+--------------------------------------+ | checksum | cd573cfaace07e7949bc0c46028904ff | | container_format | bare | | created_at | 2016-12-06T11:39:06Z | | disk_format | raw | | id | 3020a21d-ba37-4495-8899-07fc201161b9 | | min_disk | 0 | | min_ram | 0 | | name | image_from_volume1 | | owner | 5669caad86a04256994cdf755df4d3c1 | | protected | False | | size | 1085276160 | | status | active | | tags | [] | | updated_at | 2016-12-06T11:39:24Z | | virtual_size | None | | visibility | private | +------------------+--------------------------------------+ Create a new volume using the previous image (``image_id 3020a21d-ba37-4495 -8899-07fc201161b9`` in this example) as the source. Set the target volume size to 1GB; this is the size reported by the ``cinder`` tool when you uploaded the volume to the Image service: .. code-block:: console $ openstack volume create volume2 --size 1 --image 3020a21d-ba37-4495-8899-07fc201161b9 ERROR: Invalid input received: Size of specified image 2 is larger than volume size 1. (HTTP 400) (Request-ID: req-4b9369c0-dec5-4e16-a114-c0cdl6bSd210) The attempt to create a new volume based on the size reported by the ``cinder`` tool will then fail. Solution ~~~~~~~~ To work around this problem, increase the target size of the new image to the next whole number. In the problem example, you created a 1GB volume to be used as volume-backed image, so a new volume using this volume-backed image should use a size of 2GB: .. code-block:: console $ openstack volume create volume2 --size 1 --image 3020a21d-ba37-4495-8899-07fc201161b9 +---------------------+--------------------------------------+ | Field | Value | +---------------------+--------------------------------------+ | attachments | [] | | availability_zone | nova | | bootable | false | | consistencygroup_id | None | | created_at | 2016-12-06T11:49:06.031768 | | description | None | | encrypted | False | | id | a70d6305-f861-4382-84d8-c43128be0013 | | migration_status | None | | multiattach | False | | name | volume2 | | properties | | | replication_status | disabled | | size | 1 | | snapshot_id | None | | source_volid | None | | status | creating | | type | iscsi | | updated_at | None | | user_id | c36cec73b0e44876a4478b1e6cd749bb | +---------------------+--------------------------------------+ .. note:: The dashboard suggests a suitable size when you create a new volume based on a volume-backed image. You can then check this new volume into the EQL array: .. code-block:: console eql> volume select volume-64e8eb18-d23f-437b-bcac-b352afa6843a eql (volume_volume-61e8eb18-d23f-437b-bcac-b352afa6843a)> show ______________________________ Volume Information _______________________________ Name: volume-64e8eb18-d23f-437b-bcac-b352afa6843a Size: 2GB VolReserve: 2.01GB VolReserveInUse: 1.01GB ReplReserveInUse: 0MB iSCSI Alias: volume-64e8eb18-d23f-437b-bcac-b352afa6843a iSCSI Name: iqn.2001-05.com.equallogic:0-8a0906-e3091850e-eae000000b7S32cl-volume-64e8eb18-d23f-437b-bcac-b3S2afa6Bl3a ActualMembers: 1 Snap-Warn: 10% Snap-Depletion: delete-oldest Description: Snap-Reserve: 100% Snap-Reserve-Avail: 100% (2GB) Permission: read-write DesiredStatus: online Status: online Connections: 1 Snapshots: O Bind: Type: not-replicated ReplicationReserveSpace: 0MB