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Diffstat (limited to 'api-guide/source/accelerator-support.rst')
| -rw-r--r-- | api-guide/source/accelerator-support.rst | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/api-guide/source/accelerator-support.rst b/api-guide/source/accelerator-support.rst index d6f91f05e9..cf9f185273 100644 --- a/api-guide/source/accelerator-support.rst +++ b/api-guide/source/accelerator-support.rst @@ -10,8 +10,9 @@ To launch servers with accelerators, the administrator (or an user with appropriate privileges) must do the following: * Create a device profile in Cyborg, which specifies what accelerator - resources need to be provisioned. (See `Cyborg device profiles API - <https://docs.openstack.org/api-ref/accelerator/v2/index.html#device-profiles>`_. + resources need to be provisioned. (See `Cyborg device profiles API`_.) + + .. _`Cyborg device profiles API`: https://docs.openstack.org/api-ref/accelerator/v2/index.html#device-profiles * Set the device profile name as an extra spec in a chosen flavor, with this syntax: @@ -54,3 +55,28 @@ below: Some operations, such as lock and unlock, work as they are effectively no-ops for accelerators. + +Caveats +------- + +.. note:: + + This information is correct as of the 21.0.0 Ussuri release. Where + improvements have been made or issues fixed, they are noted per item. + +For nested resource providers: + +* Creating servers with accelerators provisioned with the Cyborg service, if + a flavor asks for resources that are provided by nested Resource Provider + inventories (e.g. vGPU) and the user wants multi-create (i.e. say --max 2) + then the scheduler could be returning a NoValidHosts exception even if each + nested Resource Provider can support at least one specific instance, if the + total wanted capacity is not supported by only one nested Resource Provider. + (See `bug 1874664 <https://bugs.launchpad.net/nova/+bug/1874664>`_.) + + For example, creating servers with accelerators provisioned with the Cyborg + service, if two children RPs have 4 vGPU inventories each: + + - You can ask for a device profile in the flavor with 2 vGPU with --max 2. + - But you can't ask for a device profile in the flavor with 4 vGPU and + --max 2. |