Operator call: rather than train beside gen on GPU0, move gen to GPU1 and
stand sec down for the night, so the tune gets a whole 95.60 GiB card and
the fleet's general seat never goes dark beyond its own restart.
Order is load-bearing in both directions and the playbooks enforce it.
gen runs at --gpu-memory-utilization 0.43, which vLLM reads as a fraction
of TOTAL card memory: 42,091 MiB must be FREE at startup or the engine
refuses to boot. GPU1 has 19,446 MiB free while mog-sec is up, so
recreating gen onto GPU1 first would take the main seat down and leave it
down. mog-sec stops first and a hard gate checks the freed memory before
gen is touched. The close playbook mirrors it: gen must vacate GPU1
before mog-sec starts, since mog-sec needs 50,901 MiB of its own.
Close opens with a gate that refuses to run while a process is still
resident on GPU0, so it cannot evict a training run mid-flight.
Override with --var allow_busy_gpu0=true.
Three defects found and fixed while landing this, all worth keeping:
- Verifying GPU residency via `docker inspect --format {{.State.Pid}}`
never matches. vLLM V1 runs EngineCore as a child of the container's
pid 1, and it is the child that holds the memory and that nvidia-smi
reports. Match by cgroup instead.
- A step's `sudo: true` does not extend to its when/creates/changed_when
guards, which run as the login user. The root-only .env made an
unsudo'd grep exit 2, so the GPU-id flip SILENTLY SKIPPED. The
effective-value assert is what caught it.
- That assert originally grepped the config YAML for -\s*'?1'? and failed
against compose's double-quoted `- "1"`. Parse the JSON with jq; an
assert that fails for the wrong reason is worse than no assert.
elway must be invoked as infra-ops@10.250.50.54 rather than the ana-ml2
ssh-target, which resolves to lkraven and has no NOPASSWD sudo.
vh
9d70100867