Add peft export check (NVIDIA-NeMo#13835)

Signed-off-by: Chen Cui <[email protected]>
Signed-off-by: Amir Hussein <[email protected]>

Author: cuichenx

nemo/collections/llm/recipes/qwen3_30b_a3b.py

@@ -163,7 +163,7 @@ def pretrain_recipe(
             seq_length=seq_length,
             global_batch_size=global_batch_size,
             micro_batch_size=micro_batch_size,
-            tokenizer=run.Config(AutoTokenizer, "Qwen/Qwen3-30B_A3B"),
+            tokenizer=run.Config(AutoTokenizer, "Qwen/Qwen3-30B-A3B"),
         ),
         log=default_log(dir=dir, name=name, tensorboard_logger=tensorboard_logger(name=name)),
         optim=distributed_fused_adam_with_cosine_annealing(

nemo/lightning/io/api.py

@@ -192,14 +192,26 @@ def load_connector_from_trainer_ckpt(path: Path, target: str) -> ModelConnector:
             "hf"
         )
     """
-    model: pl.LightningModule = load_context(path).model
+    model: pl.LightningModule = load_context(path, subpath="model")
 
     if not isinstance(model, ConnectorMixin):
         raise ValueError("Model must be an instance of ConnectorMixin")
 
     return model.exporter(target, path)
 
 
+def _verify_peft_export(path: Path, target: str):
+    if target == "hf" and (path / "weights" / "adapter_metadata.json").exists():
+        raise ValueError(
+            f"Your checkpoint \n`{path}`\ncontains PEFT weights, but your specified export target `hf` should be "
+            f"used for full model checkpoints. "
+            f"\nIf you want to convert NeMo 2 PEFT to Hugging Face PEFT checkpoint, set `target='hf-peft'`. "
+            f"If you want to merge LoRA weights back to the base model and export the merged full model, "
+            f"run `llm.peft.merge_lora` first before exporting. See "
+            f"https://docs.nvidia.com/nemo-framework/user-guide/latest/sft_peft/peft_nemo2.html for more details."
+        )
+
+
 def export_ckpt(
     path: Path,
     target: str,
@@ -247,6 +259,7 @@ def export_ckpt(
         nemo_ckpt_path = Path("/path/to/model.ckpt")
         export_path = export_ckpt(nemo_ckpt_path, "hf")
     """
+    _verify_peft_export(path, target)
     exporter: ModelConnector = load_connector(path, target)
     _output_path = output_path or Path(path) / target