diff --git a/src/main/java/com/kamco/cd/training/train/TrainApiController.java b/src/main/java/com/kamco/cd/training/train/TrainApiController.java
index 941278b..1c5f9d4 100644
--- a/src/main/java/com/kamco/cd/training/train/TrainApiController.java
+++ b/src/main/java/com/kamco/cd/training/train/TrainApiController.java
@@ -185,7 +185,7 @@ public class TrainApiController {
       })
   @PostMapping("/create-tmp/{uuid}")
   public ApiResponseDto<UUID> createTmpFile(
-      @Parameter(description = "uuid", example = "80a0e544-36ed-4999-b705-97427f23337d")
+      @Parameter(description = "model uuid", example = "80a0e544-36ed-4999-b705-97427f23337d")
           @PathVariable
           UUID uuid) {
 
diff --git a/src/main/java/com/kamco/cd/training/train/service/DataSetCountersService.java b/src/main/java/com/kamco/cd/training/train/service/DataSetCountersService.java
index 82eeaaa..20f5766 100644
--- a/src/main/java/com/kamco/cd/training/train/service/DataSetCountersService.java
+++ b/src/main/java/com/kamco/cd/training/train/service/DataSetCountersService.java
@@ -6,13 +6,17 @@ import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.log4j.Log4j2;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 
+/** 학습실행 파일 하드링크 */
 @Service
 @Log4j2
 @RequiredArgsConstructor
@@ -42,6 +46,10 @@ public class DataSetCountersService {
 
       // tmp
       Path tmpPath = Path.of(trainBaseDir, "tmp", basic.getRequestPath());
+
+      // 차이나는거
+      diffMergedRequestsVsTmp(uids, tmpPath);
+
       DatasetCounters counters2 = countTmpAfterBuild(tmpPath);
       allLogs
           .append(counters2.prints(basic.getRequestPath(), "TMP"))
@@ -163,4 +171,58 @@ public class DataSetCountersService {
           test + test2);
     }
   }
+
+  private Set<String> listTifRelative(Path root) throws IOException {
+    if (!Files.isDirectory(root)) return Set.of();
+
+    try (var stream = Files.walk(root)) {
+      return stream
+          .filter(Files::isRegularFile)
+          .filter(p -> p.getFileName().toString().toLowerCase().endsWith(".tif"))
+          .map(p -> root.relativize(p).toString().replace("\\", "/"))
+          .collect(Collectors.toSet());
+    }
+  }
+
+  private Set<String> listTifFileNameOnly(Path root) throws IOException {
+    if (!Files.isDirectory(root)) return Set.of();
+
+    try (var stream = Files.walk(root)) {
+      return stream
+          .filter(Files::isRegularFile)
+          .filter(p -> p.getFileName().toString().toLowerCase().endsWith(".tif"))
+          .map(p -> p.getFileName().toString()) // 파일명만
+          .collect(Collectors.toSet());
+    }
+  }
+
+  public void diffMergedRequestsVsTmp(List<String> uids, Path tmpRoot) throws IOException {
+
+    // 1) 요청 uids 전체를 합친 tif "파일명" 집합
+    Set<String> reqAll = new HashSet<>();
+    for (String uid : uids) {
+      Path reqRoot = Path.of(requestDir, uid);
+
+      // ★합본 tmp는 보통 폴더 구조가 바뀌므로 "상대경로" 비교보다 파일명 비교가 먼저 유용합니다.
+      reqAll.addAll(listTifFileNameOnly(reqRoot));
+    }
+
+    // 2) tmp tif 파일명 집합
+    Set<String> tmpAll = listTifFileNameOnly(tmpRoot);
+
+    Set<String> missing = new HashSet<>(reqAll);
+    missing.removeAll(tmpAll);
+
+    Set<String> extra = new HashSet<>(tmpAll);
+    extra.removeAll(reqAll);
+
+    log.info("==== MERGED DIFF (filename-based) ====");
+    log.info("request(all uids) tif = {}", reqAll.size());
+    log.info("tmp tif               = {}", tmpAll.size());
+    log.info("missing               = {}", missing.size());
+    log.info("extra                 = {}", extra.size());
+
+    missing.stream().sorted().limit(50).forEach(f -> log.warn("[MISSING] {}", f));
+    extra.stream().sorted().limit(50).forEach(f -> log.warn("[EXTRA] {}", f));
+  }
 }
diff --git a/src/main/java/com/kamco/cd/training/train/service/TmpDatasetService.java b/src/main/java/com/kamco/cd/training/train/service/TmpDatasetService.java
index cecceb1..183b87d 100644
--- a/src/main/java/com/kamco/cd/training/train/service/TmpDatasetService.java
+++ b/src/main/java/com/kamco/cd/training/train/service/TmpDatasetService.java
@@ -88,6 +88,7 @@ public class TmpDatasetService {
 
     // 충돌 시 덮어쓰기
     if (Files.exists(dst)) {
+      log.warn("COLLISION overwrite: dst={} src={}", dst, src);
       Files.delete(dst);
     }
 
@@ -171,8 +172,8 @@ public class TmpDatasetService {
           scannedDirs++;
           log.info("SCAN dir={}", srcDir);
 
-          try (DirectoryStream<Path> stream = Files.newDirectoryStream(srcDir)) {
-            for (Path f : stream) {
+          try (var stream = Files.walk(srcDir)) {
+            for (Path f : stream.filter(Files::isRegularFile).toList()) {
               if (!Files.isRegularFile(f)) {
                 log.debug("skip non-regular file: {}", f);
                 continue;