50 lines
2.4 KiB
YAML
50 lines
2.4 KiB
YAML
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---
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features:
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A general framework to accommodate hardware compression accelerators for
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compression of volumes uploaded to the Image service (Glance) as images
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and decompression of compressed images used to create volumes is
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introduced.
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The only accelerator supported in this release is Intel QuickAssist
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Technology (QAT), which produces a compressed file in gzip format.
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Refer to this `Cinder documentation
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<https://docs.openstack.org/cinder/latest/admin/blockstorage-accelerate-image-compression.html>`_
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for more information about using this feature.
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Additionally, the framework provides software-based compression using
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GUNzip tool if a suitable hardware accelerator is not available.
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Because this software fallback could cause performance problems if the
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Cinder services are not deployed on sufficiently powerful nodes, the
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default setting is *not* to enable compression on image upload or
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download.
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The compressed image of a volume will be stored in the
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Image service (Glance) with the ``container_format`` image property of
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``compressed``. See the `Image service documentation
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<https://docs.openstack.org/glance/latest>`_ for more information about
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this image container format.
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issues:
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In the Image service (Glance), the ``compressed`` container format
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identifier does not indicate a particular compression technology; it is up
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to the image consumer to determine what compression has been used, and
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there is no requirement that OpenStack services must support arbitrary
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compression technologies. For the upload and download of compressed
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images, Cinder supports *only* the gzip format.
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While you may expect that Cinder will be able to consume any image in
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``compressed`` container format *that Cinder has created*, you should not
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expect Cinder to be able to successfully use an image in ``compressed``
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format that it has not created itself.
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upgrade:
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Added string config option ``compression_format`` in [default] section of
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cinder.conf to specify image compression format. Currently the only legal
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value for this option is ``gzip``.
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Added boolean config option ``allow_compression_on_image_upload`` in
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[default] section of cinder.conf to enable/disable image compression on
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image upload. The default value of this option is ``false``, which means
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image compression is disabled.
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