月度归档:2025年09月

Unsolth安装 微调 lora Qlora

https://unsloth.ai


如何运行 Unsloth

1. 安装环境

Conda 安装

conda create --name unsloth_env \
    python=3.11 \
    pytorch-cuda=12.1 \
    pytorch cudatoolkit xformers -c pytorch -c nvidia -c xformers \
    -y
conda activate unsloth_env

pip install "unsloth[colab-new] @ git+https://github.com/unslothai/unsloth.git"
pip install --no-deps trl peft accelerate bitsandbytes

Pip 安装

pip install --upgrade pip
pip install "unsloth[cu121-torch240] @ git+https://github.com/unslothai/unsloth.git"

使用教程

unsloth的使用非常简单,主要分为以下几个步骤:

  1. 导入必要的库:
from unsloth import FastLanguageModel
from unsloth import is_bfloat16_supported
import torch
from trl import SFTTrainer
from transformers import TrainingArgumentsrom datasets import load_dataset
  1. 加载预训练模型:
model, tokenizer = FastLanguageModel.from_pretrained(
    model_name = "unsloth/llama-3-8b-bnb-4bit",
    max_seq_length = 2048,
    dtype = None,
    load_in_4bit = True,
)
  1. 应用LoRA进行微调:
model = FastLanguageModel.get_peft_model(
    model,
    r = 16,
    target_modules = ["q_proj", "k_proj", "v_proj", "o_proj",
                      "gate_proj", "up_proj", "down_proj",],
    lora_alpha = 16,
    lora_dropout = 0,
    bias = "none",    
    use_gradient_checkpointing = "unsloth",
    random_state = 3407,
    max_seq_length = 2048,
)
  1. 开始训练:
trainer = SFTTrainer(
    model = model,
    train_dataset = dataset,
    dataset_text_field = "text",
    max_seq_length = 2048,
    tokenizer = tokenizer,
    args = TrainingArguments(
        per_device_train_batch_size = 2,
        gradient_accumulation_steps = 4,
        warmup_steps = 10,
        max_steps = 60,
        fp16 = not is_bfloat16_supported(),
        bf16 = is_bfloat16_supported(),
        logging_steps = 1,
        output_dir = "outputs",
        optim = "adamw_8bit",
        seed = 3407,
    ),
)
trainer.train()