A served model can be moved to more cards, or fewer

llmgw ctl model gpus MODEL N [--profile P] [--in-place],
POST /api/v1/models/{name}/gpus and the console's GPUs…: how many cards of
one node each replica uses. Tensor parallel for vLLM, SGLang and
TensorRT-LLM, held to the model's KV heads (modelplan.SplitsHeads, now one
rule for the planner and this); the layers split for llama.cpp, its old
--tensor-split dropped. Refused for a count no node has, for cards that
would not hold the weights and the context, and for engines on one card.
The replicas start again beside the old ones; with no room beside them the
command says so, and --in-place stops each first.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/admin-api.openapi.json

@@ -2964,6 +2964,58 @@
         }
       }
     },
+    "/api/v1/models/{name}/gpus": {
+      "post": {
+        "operationId": "postModelsNameGpus",
+        "summary": "Spread a served model over more cards or fewer: its profile, checked against its KV heads, its cards' memory and the nodes, then its replicas restarted",
+        "description": "Tensor parallel for vLLM, SGLang and TensorRT-LLM, a layer split for llama.cpp, on one node. With no room beside the running replicas, in_place stops each first.",
+        "tags": [
+          "models"
+        ],
+        "parameters": [
+          {
+            "name": "name",
+            "in": "path",
+            "required": true,
+            "description": "The model's name in the catalog.",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/modelserve.GPUsRequest"
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/modelserve.GPUsChange"
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
     "/api/v1/models/{name}/headroom": {
       "get": {
         "operationId": "getModelsNameHeadroom",
@@ -11133,6 +11185,67 @@
           }
         }
       },
+      "modelserve.GPUsChange": {
+        "type": "object",
+        "description": "GPUsChange is what was changed, and the replicas started again on it.",
+        "properties": {
+          "model": {
+            "type": "string"
+          },
+          "profile": {
+            "type": "string"
+          },
+          "engine": {
+            "type": "string"
+          },
+          "gpu_class": {
+            "type": "string"
+          },
+          "before": {
+            "type": "integer"
+          },
+          "after": {
+            "type": "integer"
+          },
+          "args": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "per_card": {
+            "type": "string",
+            "description": "PerCard is what each card holds after, when it could be worked out."
+          },
+          "restarted": {
+            "type": "integer"
+          },
+          "in_place": {
+            "type": "boolean"
+          },
+          "note": {
+            "type": "string",
+            "description": "Note is what could not be checked, said once."
+          }
+        }
+      },
+      "modelserve.GPUsRequest": {
+        "type": "object",
+        "description": "GPUsRequest is how many cards a replica is to use.",
+        "properties": {
+          "gpus": {
+            "type": "integer"
+          },
+          "profile": {
+            "type": "string",
+            "description": "Profile is the one to change, when the model has more than one profile on cards."
+          },
+          "in_place": {
+            "type": "boolean",
+            "description": "InPlace stops each replica before its replacement starts: for when no node has the cards free beside it. It does not answer while the new one loads."
+          }
+        }
+      },
       "modelserve.Job": {
         "type": "object",
         "description": "Job is one model being served, and where it stands.",