R.1

Flags by job

The Miles flags this manual uses, grouped by the job they do.

The value column gives the setting of our lab runs where we set it. A dash means our runs did not set the flag.

Model and data

FlagOur valueWhat it sets
--hf-checkpointthe Qwen3-0.6B folderthe model that the engine and the FSDP trainer load
--prompt-datathe GSM8K training filethe prompts
--input-key, --label-keymessages, labelthe fields of each data row
--apply-chat-templateonwraps each prompt in the chat template of the model
--rollout-shuffleonshuffles the prompts

Rollout

FlagOur valueWhat it sets
--num-rollout12, 24, or 48, and 4 in the model-size runsthe number of steps
--rollout-batch-size32prompts per step
--n-samples-per-prompt8answers per prompt
--rollout-max-response-len1024, and 256 in the model-size runsthe answer limit in tokens
--rollout-temperature1the sampling temperature
--rollout-top-p, --rollout-top-k0.95, 64 in one runthe sampler, and sampling replay when set
--rollout-num-gpus-per-engine1GPUs per engine
--rollout-seedthe run seedthe sampling seed
--partial-rollout-continues long answers in a later step
--over-sampling-batch-size-the batch of new prompts when finished groups run short
--dynamic-sampling-filter-path-the group filter

Reward and loss

FlagOur valueWhat it sets
--rm-typemaththe built-in reward
--custom-rm-path-your own reward function
--advantage-estimatorgrpothe advantage method
--global-batch-size256samples per optimizer step
--eps-clip, --eps-clip-high0.2, 0.28the clip range of the update
--kl-loss-coef, --kl-coef, --entropy-coef0the KL and entropy terms
--lr1e-6the learning rate, constant
--use-tis, --tis-clip-truncated importance sampling
--use-rollout-routing-replay-routing replay for MoE models

Placement and memory

FlagOur valueWhat it sets
--colocateontrainer and engine on the same GPU, with offload
--train-backendfsdpthe trainer
--actor-num-nodes, --actor-num-gpus-per-node1, 1trainer GPUs
--sglang-mem-fraction-static0.4, 0.25 in three runs, 0.2 in one 4B runthe engine share of GPU memory
--offload-rollout-levelthe default, kv_cache in one runwhat the engine gives back between phases
--no-offload-rollout, --no-offload-trainin two runs and in one runkeep one side loaded
--update-weight-buffer-size536870912the weight update bucket, in bytes
--update-weight-transfer-mode-the weight transfer method in a split layout

Engine

FlagOur valueWhat it sets
--sglang-attention-backendthe default, or triton or flashinferthe engine attention kernel
--sglang-enable-deterministic-inferencein three runsdeterministic engine kernels
--sglang-enable-metricsonthe engine metrics
--use-session-server-token-in, token-out sessions for agents
--use-miles-router-the Python router instead of the default

Checks and debugging

FlagOur valueWhat it sets
--seedthe run seedthe trainer seed
--save-debug-event-dataa folder per runthe events of each step
--save-debug-rollout-data, --load-debug-rollout-data-saves and replays rollout samples
--debug-train-only, --debug-rollout-only-runs one side alone
--check-weight-update-equal-compares engine and trainer weights after the first update
--use-fault-tolerance, --ft-components-fault tolerance
--save, --save-interval, --load-checkpoints

Miles radixark/miles:latest, Miles main of 2026-10-15 · 08752a1 · 2026-10-15 · Edition 2026.10