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hal0

Reading the memory map

knowledge base · operating hal0·reviewed 2026-08-09·suggest an edit ↗

Every slot hal0 loads competes for the same GTT pool (see Unified memory is not VRAM). The memory map is the one command that shows what’s actually resident right now, rather than what you think you configured.

Terminal window
hal0 slots --memory
primary   qwen3.5-9b-q4kxl      6.0 GB   serving
embed     nomic-embed-text-v2   2.3 GB   ready
stt       whisper-v3.turbo      1.6 GB   idle
────────────────────────────────────────────
resident  9.9 GB / 96 GB GTT

What each state means for memory

Section titled “What each state means for memory”
  • serving / ready — fully resident, holding its full memory footprint.
  • idle — resident but not the most-recently-used; the first candidate for eviction if a new slot needs room.
  • warming / starting — mid-load; its footprint is climbing toward the steady-state number, not there yet.
  • offline — not resident at all; doesn’t appear in the memory map.

Eviction is LRU, not size-based

Section titled “Eviction is LRU, not size-based”

When a new slot needs memory the pool doesn’t have, hal0 evicts the least-recently-used idle slot first — not the largest one. A small embed slot that hasn’t been hit in an hour goes before a large agent slot that was just used, even if evicting the large one would free more room in one step.

Reading drift over time

Section titled “Reading drift over time”

The number in the memory map right after a slot reaches serving is usually its floor, not its ceiling — KV cache grows with conversation length up to the configured context window. A slot that read 6.0 GB on its first request can read several GB higher after a long session. If a box that fit fine at boot starts evicting mid-day, this is usually why — check hal0 slots --memory before assuming it’s a leak.

Section titled “Related”