diff --git a/server/src/main/java/org/apache/iotdb/db/engine/flush/VmMergeUtils.java b/server/src/main/java/org/apache/iotdb/db/engine/flush/VmMergeUtils.java
index dafba0dfa9d833669e534282db501a596c530280..4b24e314945deb84cdfe9334a3f4f56a32775a9b 100644
--- a/server/src/main/java/org/apache/iotdb/db/engine/flush/VmMergeUtils.java
+++ b/server/src/main/java/org/apache/iotdb/db/engine/flush/VmMergeUtils.java
@@ -170,6 +170,7 @@ public class VmMergeUtils {
 
     for (TsFileSequenceReader reader : tsFileSequenceReaderMap.values()) {
       reader.close();
+      logger.info("{} vm file close a reader", reader.getFileName());
     }
   }
 
@@ -179,6 +180,7 @@ public class VmMergeUtils {
     return tsFileSequenceReaderMap.computeIfAbsent(vmWriter.getFile().getAbsolutePath(),
         path -> {
           try {
+            logger.info("{} vm file create a reader", path);
             return new TsFileSequenceReader(path);
           } catch (IOException e) {
             logger.error(
diff --git a/server/src/main/java/org/apache/iotdb/db/engine/storagegroup/TsFileProcessor.java b/server/src/main/java/org/apache/iotdb/db/engine/storagegroup/TsFileProcessor.java
index 653e9a604f54744efbcdf75404e3fc782c95ca58..47bcac09c8703a89c5114ef02832457bfe786bf8 100644
--- a/server/src/main/java/org/apache/iotdb/db/engine/storagegroup/TsFileProcessor.java
+++ b/server/src/main/java/org/apache/iotdb/db/engine/storagegroup/TsFileProcessor.java
@@ -263,7 +263,8 @@ public class TsFileProcessor {
   public void deleteDataInMemory(Deletion deletion) {
     flushQueryLock.writeLock().lock();
     if (logger.isDebugEnabled()) {
-      logger.debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
+      logger
+          .debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
     }
     try {
       if (workMemTable != null) {
@@ -383,7 +384,8 @@ public class TsFileProcessor {
   void asyncClose() {
     flushQueryLock.writeLock().lock();
     if (logger.isDebugEnabled()) {
-      logger.debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
+      logger
+          .debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
     }
     try {
 
@@ -391,7 +393,8 @@ public class TsFileProcessor {
         if (workMemTable != null) {
           logger.info(
               "{}: flush a working memtable in async close tsfile {}, memtable size: {}, tsfile size: {}",
-              storageGroupName, tsFileResource.getTsFile().getAbsolutePath(), workMemTable.memSize(),
+              storageGroupName, tsFileResource.getTsFile().getAbsolutePath(),
+              workMemTable.memSize(),
               tsFileResource.getTsFileSize());
         } else {
           logger.info("{}: flush a NotifyFlushMemTable in async close tsfile {}, tsfile size: {}",
@@ -442,7 +445,8 @@ public class TsFileProcessor {
     IMemTable tmpMemTable;
     flushQueryLock.writeLock().lock();
     if (logger.isDebugEnabled()) {
-      logger.debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
+      logger
+          .debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
     }
     try {
       tmpMemTable = workMemTable == null ? new NotifyFlushMemTable() : workMemTable;
@@ -485,7 +489,8 @@ public class TsFileProcessor {
   public void asyncFlush() {
     flushQueryLock.writeLock().lock();
     if (logger.isDebugEnabled()) {
-      logger.debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
+      logger
+          .debug(FLUSH_QUERY_WRITE_LOCKED, storageGroupName, tsFileResource.getTsFile().getName());
     }
     try {
       if (workMemTable == null) {
@@ -621,7 +626,8 @@ public class TsFileProcessor {
         writer.getIOWriterOut().truncate(result.right - 1);
         VmMergeUtils.fullMerge(writer, vmWriters,
             storageGroupName,
-            new VmLogger(tsFileResource.getTsFile().getParent(), tsFileResource.getTsFile().getName()),
+            new VmLogger(tsFileResource.getTsFile().getParent(),
+                tsFileResource.getTsFile().getName()),
             deviceSet, sequence);
         for (TsFileResource vmTsFileResource : vmTsFileResources) {
           deleteVmFile(vmTsFileResource);
@@ -782,8 +788,14 @@ public class TsFileProcessor {
       // on other merge task working now, it's safe to submit one.
       if (!mergeWorking) {
         mergeWorking = true;
+        logger.info("{}: {} submit a vm merge task", storageGroupName,
+            tsFileResource.getTsFile().getName());
         VmMergeTaskPoolManager.getInstance()
-            .submit(new VmMergeTask(new ArrayList<>(vmTsFileResources), new ArrayList<>(vmWriters)));
+            .submit(
+                new VmMergeTask(new ArrayList<>(vmTsFileResources), new ArrayList<>(vmWriters)));
+      } else {
+        logger.info("{}: {} last vm merge task is working, skip current merge", storageGroupName,
+            tsFileResource.getTsFile().getName());
       }
     }
   }
@@ -1001,14 +1013,17 @@ public class TsFileProcessor {
 
     @Override
     public void run() {
+      long startTimeMillis = System.currentTimeMillis();
       try {
+        logger.info("{}: {} start to run vm merge task", storageGroupName,
+            tsFileResource.getTsFile().getName());
         long vmPointNum = 0;
         // all flush to target file
         Map<Path, MeasurementSchema> pathMeasurementSchemaMap = new HashMap<>();
         for (RestorableTsFileIOWriter vmWriter : vmMergeWriters) {
           Map<String, Map<String, List<ChunkMetadata>>> schemaMap = vmWriter
               .getMetadatasForQuery();
-          for(Entry<String, Map<String, List<ChunkMetadata>>> schemaMapEntry : schemaMap
+          for (Entry<String, Map<String, List<ChunkMetadata>>> schemaMapEntry : schemaMap
               .entrySet()) {
             String device = schemaMapEntry.getKey();
             for (Entry<String, List<ChunkMetadata>> entry : schemaMapEntry.getValue().entrySet()) {
@@ -1022,17 +1037,21 @@ public class TsFileProcessor {
             }
           }
         }
+        logger.info("{}: {} current vm point num: {}, measurement num: {}", storageGroupName,
+            tsFileResource.getTsFile().getName(), vmPointNum, pathMeasurementSchemaMap.size());
         if (pathMeasurementSchemaMap.size() > 0
             && vmPointNum / pathMeasurementSchemaMap.size() > config
             .getMergeChunkPointNumberThreshold() || flushVmTimes >= config
             .getMaxMergeChunkNumInTsFile()) {
           // merge vm to tsfile
           flushVmTimes = 0;
-          logger.info("[Flush] merge {} vms to TsFile", vmMergeWriters.size() + 1);
+          logger.info("{}: {} merge {} vms to TsFile", storageGroupName,
+              tsFileResource.getTsFile().getName(), vmMergeWriters.size());
           flushAllVmToTsFile(vmMergeWriters, vmMergeTsFiles);
         } else if (config.getMaxVmNum() <= vmMergeTsFiles.size()) {
           // merge vm files
-          logger.info("[Flush] merge {} vms to vm", vmMergeTsFiles.size() + 1);
+          logger.info("{}: {} merge {} vms to vm", storageGroupName,
+              tsFileResource.getTsFile().getName(), vmMergeTsFiles.size());
           // merge all vm files into a new vm file
           File tmpFile = createNewTmpFile();
           RestorableTsFileIOWriter tmpWriter = new RestorableTsFileIOWriter(tmpFile);
@@ -1044,22 +1063,29 @@ public class TsFileProcessor {
           if (!tmpFile.renameTo(mergedFile)) {
             logger.error("Failed to rename {} to {}", newVmFile, mergedFile);
           }
+          logger.info("{}: {} vm merge starts to delete file", storageGroupName,
+              tsFileResource.getTsFile().getName());
           for (TsFileResource vmTsFileResource : vmMergeTsFiles) {
             deleteVmFile(vmTsFileResource);
           }
           vmWriters.removeAll(vmMergeWriters);
           vmTsFileResources.removeAll(vmMergeTsFiles);
+          logger.info("{}: {} vm merge end file", storageGroupName,
+              tsFileResource.getTsFile().getName());
           if (!mergedFile.renameTo(newVmFile)) {
             logger.error("Failed to rename {} to {}", mergedFile, newVmFile);
           }
           vmTsFileResources.add(0, new TsFileResource(newVmFile));
           vmWriters.add(0, new RestorableTsFileIOWriter(newVmFile));
+          logger.info("{} vm file close a writer", newVmFile.getName());
         }
       } catch (Exception e) {
         logger.error("Error occurred in Vm Merge thread", e);
       } finally {
         // reset the merge working state to false
         mergeWorking = false;
+        logger.info("{}: {} vm merge end time consumption: {} ms", storageGroupName,
+            tsFileResource.getTsFile().getName(), System.currentTimeMillis() - startTimeMillis);
       }
     }