vllm-project/vllm · error · MoRIIOError

Failed to register local memory: {e}

Error message

Failed to register local memory: {e}

What it means

Error "Failed to register local memory: {e}" thrown in vllm-project/vllm.

Source

Thrown at vllm/distributed/kv_transfer/kv_connector/v1/moriio/moriio_engine.py:604

    def register_remote_engine(self, remote_packed_engine_metadata):
        assert self.moriio_engine is not None, "MoRIIO engine must be set first"
        consumer_engine_metadata = EngineDesc.unpack(remote_packed_engine_metadata)
        self.moriio_engine.register_remote_engine(consumer_engine_metadata)
        return consumer_engine_metadata.key

    def register_local_tensor(self, tensor: torch.Tensor):
        assert self.moriio_engine is not None, "MoRIIO engine must be set first"
        try:
            self.local_memory_metadata = self.moriio_engine.register_torch_tensor(
                tensor
            )
            assert self.local_memory_metadata is not None, (
                "register_torch_tensor returned None"
            )
            local_memory_metadata_packed = self.local_memory_metadata.pack()
        except Exception as e:
            raise MoRIIOError(f"Failed to register local memory: {e}") from e
        self.local_memory_registered = True
        return local_memory_metadata_packed

    def get_unpack_memory_metadata(self, packed_memory_metadata):
        return MemoryDesc.unpack(packed_memory_metadata)

    def build_session(self, local_memory_metadata, remote_memory_metadata):
        assert self.moriio_engine is not None, "MoRIIO engine must be set first"
        return self.moriio_engine.create_session(
            local_memory_metadata, remote_memory_metadata
        )

    def read_remote_data(
        self, transfer_size_byte, local_offset=0, remote_offset=0, session=None
    ):
        assert self.local_memory_registered, "You have not register local memory data!"
        assert self.moriio_engine is not None, "MoRIIO engine must be set first"
        transfer_status = session.batch_read(

View on GitHub (pinned to c794754062)

Solutions

1. Check the wrapped error for why local memory registration failed (permissions, RDMA configuration, or invalid buffer).

When it happens

Trigger: Raised at vllm/distributed/kv_transfer/kv_connector/v1/moriio/moriio_engine.py:604 when validation fails: Failed to register local memory. Typically triggered by an incompatible or incomplete vLLM configuration, an unsupported platform/backend combination, or a runtime resource/dependency that is missing.

Common situations: Commonly encountered at vllm/distributed/kv_transfer/kv_connector/v1/moriio/moriio_engine.py:604 during vLLM startup/config validation or runtime setup when: (1) conflicting CLI flags or config fields are combined, (2) the current platform (CUDA/ROCm/CPU/XPU) or installed optional packages do not support the requested feature, or (3) a required value is absent or out of range. Resolve by correcting the configuration as described in the message, or by selecting a supported alternative.

AI-assisted analysis of vllm-project/vllm@c794754062 (2026-08-14). Data as JSON: /api/errors/c64e04acd5b21af1. Report an issue: GitHub.