diff --git a/plugin/localstorage/src/main/java/org/zstack/storage/primary/local/LocalStorageKvmBackend.java b/plugin/localstorage/src/main/java/org/zstack/storage/primary/local/LocalStorageKvmBackend.java
index 3b78ffab51b..2a8d442fc52 100755
--- a/plugin/localstorage/src/main/java/org/zstack/storage/primary/local/LocalStorageKvmBackend.java
+++ b/plugin/localstorage/src/main/java/org/zstack/storage/primary/local/LocalStorageKvmBackend.java
@@ -1181,6 +1181,11 @@ public void run(List<MessageReply> replies) {
 
                     ret.totalPhysicalSize += rsp.getTotalCapacity();
                     ret.availablePhysicalSize += rsp.getAvailableCapacity();
+
+                    if (rsp.getTotalCapacity() != null && rsp.getAvailableCapacity() != null) {
+                        new LocalStorageCapacityUpdater().updatePhysicalCapacityByKvmAgentResponse(
+                                self.getUuid(), hostUuid, rsp);
+                    }
                 }
 
                 completion.success(ret);
diff --git a/test/src/test/groovy/org/zstack/test/integration/storage/primary/local/LocalStorageSyncPhysicalCapacityCase.groovy b/test/src/test/groovy/org/zstack/test/integration/storage/primary/local/LocalStorageSyncPhysicalCapacityCase.groovy
new file mode 100644
index 00000000000..cc6dfe39558
--- /dev/null
+++ b/test/src/test/groovy/org/zstack/test/integration/storage/primary/local/LocalStorageSyncPhysicalCapacityCase.groovy
@@ -0,0 +1,108 @@
+package org.zstack.test.integration.storage.primary.local
+
+import org.zstack.core.db.Q
+import org.zstack.sdk.PrimaryStorageInventory
+import org.zstack.storage.primary.local.LocalStorageHostRefVO
+import org.zstack.storage.primary.local.LocalStorageHostRefVO_
+import org.zstack.test.integration.kvm.Env
+import org.zstack.testlib.EnvSpec
+import org.zstack.testlib.LocalStorageSpec
+import org.zstack.testlib.SubCase
+import org.zstack.utils.data.SizeUnit
+
+/**
+ * Test for ZSTAC-82207:
+ * After migrating snapshot group data away from a local storage PS,
+ * syncPrimaryStorageCapacity should update availablePhysicalCapacity
+ * to reflect the actual physical disk state (from agent), not stale
+ * values from LocalStorageHostRefVO.
+ *
+ * Root cause: syncPhysicalCapacityInCluster did not update per-host
+ * LocalStorageHostRefVO.availablePhysicalCapacity, so the subsequent
+ * calculateTotalCapacity overwrote PrimaryStorageCapacityVO with stale values.
+ */
+class LocalStorageSyncPhysicalCapacityCase extends SubCase {
+    EnvSpec env
+
+    @Override
+    void setup() {
+        spring {
+            sftpBackupStorage()
+            localStorage()
+            virtualRouter()
+            securityGroup()
+            kvm()
+        }
+    }
+
+    @Override
+    void environment() {
+        env = Env.oneVmBasicEnv()
+    }
+
+    @Override
+    void test() {
+        env.create {
+            testSyncPhysicalCapacityUpdatesHostRef()
+        }
+    }
+
+    /**
+     * Verify that syncPrimaryStorageCapacity updates both:
+     * 1. PrimaryStorageCapacityVO.availablePhysicalCapacity (PS-level)
+     * 2. LocalStorageHostRefVO.availablePhysicalCapacity (per-host)
+     *
+     * This ensures calculateTotalCapacity (step 2 of sync) uses fresh
+     * physical values, not stale ones.
+     */
+    void testSyncPhysicalCapacityUpdatesHostRef() {
+        PrimaryStorageInventory ps = env.inventoryByName("local")
+        LocalStorageSpec lspec = env.specByName("local") as LocalStorageSpec
+
+        // 1. Get initial physical capacity
+        PrimaryStorageInventory psInv = queryPrimaryStorage {
+            conditions = ["uuid=${ps.uuid}".toString()]
+        }[0]
+        long initialPhysicalAvail = psInv.availablePhysicalCapacity
+
+        // Also check host ref
+        long initialHostRefPhysicalAvail = Q.New(LocalStorageHostRefVO.class)
+                .eq(LocalStorageHostRefVO_.primaryStorageUuid, ps.uuid)
+                .select(LocalStorageHostRefVO_.availablePhysicalCapacity)
+                .findValue() as long
+
+        // 2. Simulate physical capacity change: e.g., snapshot data removed from disk,
+        //    so physical available capacity increased by 2GB
+        long increase = SizeUnit.GIGABYTE.toByte(2)
+        long newAvail = initialPhysicalAvail + increase
+        lspec.availableCapacity = newAvail
+
+        // 3. Sync primary storage capacity
+        syncPrimaryStorageCapacity {
+            primaryStorageUuid = ps.uuid
+        }
+
+        // 4. Verify PS-level availablePhysicalCapacity is updated
+        retryInSecs(3) {
+            psInv = queryPrimaryStorage {
+                conditions = ["uuid=${ps.uuid}".toString()]
+            }[0]
+            assert psInv.availablePhysicalCapacity == newAvail :
+                    "PS availablePhysicalCapacity should be ${newAvail}, but got ${psInv.availablePhysicalCapacity}"
+        }
+
+        // 5. Verify host ref is also updated (this was the bug - host ref was stale)
+        long updatedHostRefPhysicalAvail = Q.New(LocalStorageHostRefVO.class)
+                .eq(LocalStorageHostRefVO_.primaryStorageUuid, ps.uuid)
+                .select(LocalStorageHostRefVO_.availablePhysicalCapacity)
+                .findValue() as long
+
+        assert updatedHostRefPhysicalAvail == newAvail :
+                "LocalStorageHostRefVO.availablePhysicalCapacity should be ${newAvail}, but got ${updatedHostRefPhysicalAvail}"
+    }
+
+    @Override
+    void clean() {
+        env.delete()
+    }
+}