SFTTrainer - psutil is not defined

[cghall19]

Hi,

I am trying to run some fairly simple examples, but when running the SFTTrainer it's throwing a psutil is not defined deep in the SFTTrainer. The exact same thing happens running locally and using google collab.

--> 854 train_dataset = self._prepare_dataset(
855 train_dataset, processing_class, args, args.packing, formatting_func, "train"
856 )
857 if eval_dataset is not None:
858 packing = args.packing if args.eval_packing is None else args.eval_packing

File ~/code/FineTuning/aviation/unsloth_compiled_cache/UnslothSFTTrainer.py:1026, in _UnslothSFTTrainer._prepare_dataset(self, dataset, processing_class, args, packing, formatting_func, dataset_name)
1024 dataset_num_proc = getattr(args, "dataset_num_proc", None)
1025 if dataset_num_proc is None:
-> 1026 dataset_num_proc = max(psutil.cpu_count()+4, 2)
1027 # Check memory left so we can reduce multiprocessing to converse memory
1028 memory_gb_left = psutil.virtual_memory().available / (1024**3)

NameError: name 'psutil' is not defined

Not sure where to go with this, looks like a dependancy issue within this version?

Thanks
Chris

[kevinchien920819]

Hi I have same problem with you too, It looks like environmental problem.
I have sloved this problem after using the official notebook to install the package.

You can access the link to get more information
Hope it help you!

[MarioAlonsoAlonso]

where is the official notebook? I can't solve this problem

[kevinchien920819]

diffent model will have diffrent notebook
check it on the link below
https://docs.unsloth.ai/get-started/unsloth-notebooks

[cghall19]

I was able to find the issue and fix... basically I had to switch from using args = TrainingArguments ( etc etc in my SFTTrainer definition to args = SFTConfig (etc etc.

[xXMrNidaXx]

The psutil is not defined error usually means psutil isn't imported or installed in the environment.

Quick fixes:

1. Install psutil

pip install psutil

2. Check import in your script

import psutil  # Make sure this is at the top

3. Environment isolation issue
If using notebooks/Colab:

!pip install psutil
import psutil

4. Unsloth dependency mismatch
Sometimes Unsloth's install doesn't pull all deps:

pip install unsloth[all]
# or
pip install unsloth psutil

5. Virtual environment check

which python
pip list | grep psutil

Make sure you're in the right env!

Root cause: SFTTrainer uses psutil for memory monitoring during training. It's usually auto-installed but can get missed in some setups.

We run into this occasionally at RevolutionAI when spinning up fresh training environments. The explicit pip install always fixes it.

Did this solve it?