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3.2 KiB
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138 lines
3.2 KiB
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..
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This work is licensed under a Creative Commons Attribution 3.0 Unported
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License.
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http://creativecommons.org/licenses/by/3.0/legalcode
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=====================================
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Add support for chiscsi iscsi helper
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=====================================
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https://blueprints.launchpad.net/cinder/+spec/chiscsi-iscsi-helper
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The Chelsio iSCSI target(chiscsi) serves as a drop in replacement for the IET
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target, aiming to provide the same functionality as IET. This spec aims at
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adding support for said target implementation as a pure iscsi_helper.
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chiscsi supports offloading of iSCSI PDU's when required hardware (supported
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Chelsio Network cards) is available but will work on any regular NIC as well.
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Offloading or lack thereof requires no user intervention once target drivers
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are installed. Implementation is initiator agnostic as well, no changes needed
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on initiator side.
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Problem description
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===================
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chiscsi target is not currently supported by openstack
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* For a Deployer trying to use offloaded iSCSI support on target side, no
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option is currently available.
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* Manual intervention is currently required to export volumes, as cinder does
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not understand chiscsi target implementation.
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Use Cases
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=========
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Proposed change
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===============
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Add one more iscsi_helper option to cover chiscsi, the driver for this will
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interact with the chiscsi target implementation to provide same functionality
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as iet.
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Use of offloading is dependent on required hardware being present but is
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completely optional. No intervention is required to enable offload and
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offloading will happen in a manner completely transparent to initiator side.
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No initiator side changes are required to make use of chiscsi, with or without
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offload support. No extra configuration options are required.
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Alternatives
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------------
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None
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Data model impact
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-----------------
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None
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REST API impact
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---------------
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None
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Security impact
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---------------
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None
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Notifications impact
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--------------------
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None
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Other end user impact
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---------------------
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None
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Performance Impact
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------------------
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If iSCSI offload is available, there is a significant performance boost to be
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gained. If offloading is not used, performance and resource usage would be
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roughly on par with IET or better.
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Other deployer impact
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---------------------
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* No new config options are required besides an extra allowed value for
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'iscsi_helper' that would need to be explicitly set to 'chiscsi'.
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* chiscsi target needs to be installed before it can be used.
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Developer impact
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----------------
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None
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Implementation
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==============
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Assignee(s)
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-----------
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Primary assignee:
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anish7
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Other contributors:
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kxie
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Work Items
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----------
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Using iet helper as base, create iscsi_helper for chiscsi, with equivalent
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commands for all required apis
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Dependencies
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============
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* Ability to use chiscsi target obviously depends on target driver being
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installed, and command utility available on path. No other dependencies
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Testing
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=======
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Current test for IET target should work just fine for chiscsi
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Documentation Impact
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====================
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None except listing chiscsi as an available iscsi_helper
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References
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==========
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* http://www.chelsio.com/iscsi-target-software/
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