198 lines
8.4 KiB
ReStructuredText
198 lines
8.4 KiB
ReStructuredText
========================================================================
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Addressing discrepancies in reported volume sizes for EqualLogic storage
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========================================================================
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Problem
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~~~~~~~
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There is a discrepancy between both the actual volume size in EqualLogic
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(EQL) storage and the image size in the Image service, with what is
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reported to OpenStack database. This could lead to confusion
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if a user is creating volumes from an image that was uploaded from an EQL
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volume (through the Image service). The image size is slightly larger
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than the target volume size; this is because EQL size reporting accounts
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for additional storage used by EQL for internal volume metadata.
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To reproduce the issue follow the steps in the following procedure.
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This procedure assumes that the EQL array is provisioned, and that
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appropriate configuration settings have been included in
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``/etc/cinder/cinder.conf`` to connect to the EQL array.
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Create a new volume. Note the ID and size of the volume. In the
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following example, the ID and size are
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``74cf9c04-4543-47ae-a937-a9b7c6c921e7`` and ``1``, respectively:
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.. code-block:: console
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$ cinder create --display-name volume1 1
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+-----------------------+-------------------------------------------+
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| Property | Value |
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+-----------------------+-------------------------------------------+
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| attachments | [] |
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| availability zone | nova |
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| bootable | false |
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| created_at | 2014-03-21T18:31:54.248775 |
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| display_description | None |
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| display_name | volume1 |
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| id | 74cf9c04-4543-47ae-a937-a9b7c6c921e7 |
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| metadata | {} |
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| size | 1 |
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| snapshot_id | None |
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| source volid | None |
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| status | creating |
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| volume type | None |
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+-----------------------+-------------------------------------------+
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Verify the volume size on the EQL array by using its command-line
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interface.
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The actual size (``VolReserve``) is 1.01 GB. The EQL Group Manager
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should also report a volume size of 1.01 GB:
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.. code-block:: console
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eql> volume select volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7
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eql (volume_volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7)> show
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_______________________________ Volume Information ________________________________
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Name: volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7
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Size: 1GB
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VolReserve: 1.01GB
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VolReservelnUse: 0MB
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ReplReservelnUse: 0MB
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iSCSI Alias: volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7
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iSCSI Name: iqn.2001-05.com.equallogic:0-8a0906-19f91850c-067000000b4532cl-volume-74cf9c04-4543-47ae-a937-a9b7c6c921e7
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ActualMembers: 1
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Snap-Warn: 10%
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Snap-Depletion: delete-oldest
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Description:
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Snap-Reserve: 100%
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Snap-Reserve-Avail: 100% (1.01GB)
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Permission: read-write
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DesiredStatus: online
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Status: online
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Connections: O
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Snapshots: O
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Bind:
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Type: not-replicated
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ReplicationReserveSpace: 0MB
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Create a new image from this volume:
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.. code-block:: console
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$ cinder upload-to-image --disk-format raw \
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--container-format bare volume1 image_from_volume1
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+---------------------+---------------------------------------+
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| Property | Value |
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+---------------------+---------------------------------------+
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| container_format | bare |
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| disk_format | raw |
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| display_description | None |
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| id | 74cf9c04-4543-47ae-a937-a9b7c6c921e7 |
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| image_id | 3020a21d-ba37-4495-8899-07fc201161b9 |
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| image_name | image_from_volume1 |
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| size | 1 |
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| status | uploading |
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| updated_at | 2014-03-21T18:31:55.000000 |
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| volume_type | None |
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+---------------------+---------------------------------------+
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When you uploaded the volume in the previous step, the Image service
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reported the volume's size as ``1`` (GB). However, when using
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:command:`glance image-list` to list the image, the displayed size is
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1085276160 bytes, or roughly 1.01 GB:
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+-----------------------+---------+-----------+--------------+--------------+
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| Name | Disk | Container | Size | Status |
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| | Format | Format | | |
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+=======================+=========+===========+==============+==============+
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| image\_from\_volume1 | raw | bare | *1085276160* | active |
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+-----------------------+---------+-----------+--------------+--------------+
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Create a new volume using the previous image (``image_id 3020a21d-ba37-4495
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-8899-07fc201161b9`` in this example) as
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the source. Set the target volume size to 1 GB; this is the size
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reported by the ``cinder`` tool when you uploaded the volume to the
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Image service:
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.. code-block:: console
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$ cinder create --display-name volume2 \
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--image-id 3020a21d-ba37-4495-8899-07fc201161b9 1
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ERROR: Invalid input received: Size of specified image 2 is larger
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than volume size 1. (HTTP 400) (Request-ID: req-4b9369c0-dec5-4e16-a114-c0cdl6bSd210)
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The attempt to create a new volume based on the size reported by the
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``cinder`` tool will then fail.
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Solution
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~~~~~~~~
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To work around this problem, increase the target size of the new image
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to the next whole number. In the problem example, you created a 1 GB
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volume to be used as volume-backed image, so a new volume using this
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volume-backed image should use a size of 2 GB:
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.. code-block:: console
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$ cinder create --display-name volume2 \
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--image-id 3020a21d-ba37-4495-8899-07fc201161b9 1
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+---------------------+--------------------------------------+
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| Property | Value |
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+---------------------+--------------------------------------+
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| attachments | [] |
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| availability_zone | nova |
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| bootable | false |
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| created_at | 2014-03-21T19:25:31.564482 |
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| display_description | None |
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| display_name | volume2 |
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| id | 64e8eb18-d23f-437b-bcac-b3S2afa6843a |
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| image_id | 3020a21d-ba37-4495-8899-07fc20116lb9 |
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| metadata | [] |
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| size | 2 |
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| snapshot_id | None |
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| source_volid | None |
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| status | creating |
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| volume_type | None |
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+---------------------+--------------------------------------+
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.. note::
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The dashboard suggests a suitable size when you create a new volume
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based on a volume-backed image.
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You can then check this new volume into the EQL array:
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.. code-block:: console
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eql> volume select volume-64e8eb18-d23f-437b-bcac-b352afa6843a
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eql (volume_volume-61e8eb18-d23f-437b-bcac-b352afa6843a)> show
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______________________________ Volume Information _______________________________
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Name: volume-64e8eb18-d23f-437b-bcac-b352afa6843a
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Size: 2GB
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VolReserve: 2.01GB
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VolReserveInUse: 1.01GB
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ReplReserveInUse: 0MB
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iSCSI Alias: volume-64e8eb18-d23f-437b-bcac-b352afa6843a
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iSCSI Name: iqn.2001-05.com.equallogic:0-8a0906-e3091850e-eae000000b7S32cl-volume-64e8eb18-d23f-437b-bcac-b3S2afa6Bl3a
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ActualMembers: 1
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Snap-Warn: 10%
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Snap-Depletion: delete-oldest
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Description:
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Snap-Reserve: 100%
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Snap-Reserve-Avail: 100% (2GB)
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Permission: read-write
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DesiredStatus: online
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Status: online
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Connections: 1
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Snapshots: O
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Bind:
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Type: not-replicated
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ReplicationReserveSpace: 0MB
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