diff --git a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VfsData.java b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VfsData.java
index 4685cabd0054..b45c38c28e06 100644
--- a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VfsData.java
+++ b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VfsData.java
@@ -17,6 +17,7 @@ package com.intellij.openapi.vfs.newvfs.impl;
 
 import com.intellij.openapi.application.ApplicationAdapter;
 import com.intellij.openapi.application.ApplicationManager;
+import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.vfs.InvalidVirtualFileAccessException;
 import com.intellij.openapi.vfs.newvfs.persistent.FSRecords;
 import com.intellij.util.ArrayUtil;
@@ -73,6 +74,7 @@ import static com.intellij.util.ObjectUtils.assertNotNull;
  * @author peter
  */
 public class VfsData {
+  private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.vfs.newvfs.impl.VfsData");
   private static final int SEGMENT_BITS = 9;
   private static final int SEGMENT_SIZE = 1 << SEGMENT_BITS;
   private static final int OFFSET_MASK = SEGMENT_SIZE - 1;
@@ -223,6 +225,9 @@ public class VfsData {
     }
 
     void setFlag(int id, int mask, boolean value) {
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Set flag " + Integer.toHexString(mask) + "=" + value + " for id=" + id);
+      }
       assert (mask & ~ALL_FLAGS_MASK) == 0 : "Unexpected flag";
       int offset = getOffset(id) * 2 + 1;
       while (true) {
diff --git a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java
index d47bdd808339..16ed50c905d2 100644
--- a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java
@@ -1061,7 +1061,7 @@ public class PersistentFSImpl extends PersistentFS implements ApplicationCompone
         else if (VirtualFile.PROP_WRITABLE.equals(propertyChangeEvent.getPropertyName())) {
           executeSetWritable(file, ((Boolean)newValue).booleanValue());
           if (LOG.isDebugEnabled()) {
-            LOG.debug("File " + file + " writable=" + file.isWritable());
+            LOG.debug("File " + file + " writable=" + file.isWritable() + " id=" + getFileId(file));
           }
         }
         else if (VirtualFile.PROP_HIDDEN.equals(propertyChangeEvent.getPropertyName())) {