Fitting huge models on multiple nodes
I am trying to fit big MoE models in a multi-host, multi-GPU setup using deepspeed stage 2 or 3 for full finetuning. I tried a number of settings, with both smallerfacebook/opt-350mas well asdeepseek-ai/DeepSeek-Coder-V2-Lite-Base. The observations are that turning multinode on doesn’t decrease memory usage / doesn’t help fitting the big model into the GPU.Am I doing something obviously wrong with example settings below? In both of them I observed the ~same memory usage (on each gpu) when swapping from 1 machine to 2.Is my expectation for a ~2x decrease in memory usage of a particular GPU when scaling from 1 machine to 2 with zero stage 3 wrong?How do I debug this more? I sawthis guidebut it didn’t help me understand the issue.compute_environment: LOCAL_MACHINE
debug: false
deepspeed_config:
  gradient_accumulation_steps: 1
  offload_optimizer_device: cpu
  offload_param_device: none
  zero3_init_flag: false
  zero_stage: 2
distributed_type: DEEPSPEED
downcast_bf16: 'no'
dynamo_config:
  dynamo_backend: INDUCTOR
enable_cpu_affinity: false
machine_rank: 0
main_training_function: main
mixed_precision: bf16
num_machines: 1
num_processes: 8
rdzv_backend: static
same_network: true
tpu_env: []
tpu_use_cluster: false
tpu_use_sudo: false
use_cpu: falseanother:compute_environment: LOCAL_MACHINE
debug: false
deepspeed_config:
  deepspeed_hostfile: /home/ubuntu/code/hostfile
  deepspeed_multinode_launcher: pdsh
distributed_type: DEEPSPEED
downcast_bf16: 'no'
dynamo_config:
  dynamo_backend: INDUCTOR
enable_cpu_affinity: false
machine_rank: 0
main_process_ip: my_ip
main_process_port: 57313
main_training_function: main
num_machines: 2
num_processes: 16
rdzv_backend: static
same_network: false
tpu_env: []
tpu_use_cluster: false
tpu_use_sudo: false
use_cpu: false{
    "zero_optimization": {
       "stage": 3,
       "allgather_partitions": true,
       "allgather_bucket_size": 5e8,
       "reduce_scatter": true,
       "reduce_bucket_size": 5e8,
       "overlap_comm": false,
       "contiguous_gradients": false,
       "offload_optimizer": {
           "device": "cpu"
       },
       "offload_param": {
           "device": "none"
       }
    },
    "optimizer": {
      "type": "Adam",
      "params": {
        "lr": "auto",
        "weight_decay": "auto",
        "bias_correction": true,
        "betas": "auto",
        "eps": 1e-8
      }
    },
    "use_node_local_storage": true,
    "zero_allow_untested_optimizer": true,
    "train_micro_batch_size_per_gpu": "auto",
    "mixed_precision": "bf16",
    "round_robin_gradients": true
}