Index: oak-run/src/main/java/org/apache/jackrabbit/oak/run/Main.java
===================================================================
--- oak-run/src/main/java/org/apache/jackrabbit/oak/run/Main.java	(revision 1726966)
+++ oak-run/src/main/java/org/apache/jackrabbit/oak/run/Main.java	(working copy)
@@ -332,6 +332,7 @@
         final OptionSpec<Integer> port = parser.accepts("port", "master port").withRequiredArg().ofType(Integer.class).defaultsTo(defaultPort);
         final OptionSpec<Integer> interval = parser.accepts("interval", "interval between successive executions").withRequiredArg().ofType(Integer.class);
         final OptionSpec<Boolean> secure = parser.accepts("secure", "use secure connections").withRequiredArg().ofType(Boolean.class);
+        final OptionSpec<Void> forceFlag = parser.accepts("force", "Ignore non matching segment version");
         final OptionSpec<?> help = parser.acceptsAll(asList("h", "?", "help"), "show help").forHelp();
         final OptionSpec<String> nonOption = parser.nonOptions(Mode.STANDBY + " <path to repository>");
 
@@ -348,6 +349,8 @@
             System.exit(1);
         }
 
+        checkFileStoreVersionOrFail(new File(nonOptions.get(0)), options.has(forceFlag));
+
         FileStore store = null;
         StandbyClient failoverClient = null;
         try {
@@ -382,6 +385,7 @@
         final OptionSpec<Integer> port = parser.accepts("port", "port to listen").withRequiredArg().ofType(Integer.class).defaultsTo(defaultPort);
         final OptionSpec<Boolean> secure = parser.accepts("secure", "use secure connections").withRequiredArg().ofType(Boolean.class);
         final OptionSpec<String> admissible = parser.accepts("admissible", "list of admissible slave host names or ip ranges").withRequiredArg().ofType(String.class);
+        final OptionSpec<Void> forceFlag = parser.accepts("force", "Ignore non matching segment version");
         final OptionSpec<?> help = parser.acceptsAll(asList("h", "?", "help"), "show help").forHelp();
         final OptionSpec<String> nonOption = parser.nonOptions(Mode.PRIMARY + " <path to repository>");
 
@@ -398,6 +402,7 @@
             System.exit(1);
         }
 
+        checkFileStoreVersionOrFail(new File(nonOptions.get(0)), options.has(forceFlag));
 
         List<String> admissibleSlaves = options.has(admissible) ? options.valuesOf(admissible) : Collections.EMPTY_LIST;
 
@@ -622,6 +627,45 @@
                 .create();
     }
 
+    private static FileStore openReadOnlyFileStore(File directory) throws IOException {
+        return newFileStore(directory)
+                .withCacheSize(256)
+                .withMemoryMapping(TAR_STORAGE_MEMORY_MAPPED)
+                .withReadOnly(true)
+                .create();
+    }
+
+    private static void checkFileStoreVersionOrFail(File directory, boolean force) throws IOException {
+        if (!directory.exists()) {
+            return;
+        }
+
+        if (!directory.isDirectory()) {
+            return;
+        }
+
+        FileStore store = null;
+
+        try {
+            store = openReadOnlyFileStore(directory);
+
+            SegmentVersion segmentVersion = getSegmentVersion(store);
+
+            if (segmentVersion != LATEST_VERSION) {
+                if (force) {
+                    System.out.printf("Segment version mismatch. Found %s, expected %s. Upgrading the file store to segment version %s.\n", segmentVersion, LATEST_VERSION, LATEST_VERSION);
+                } else {
+                    failWith(String.format("Segment version mismatch. Found %s, expected %s. Aborting.", segmentVersion, LATEST_VERSION));
+                }
+            }
+        } finally {
+            if (store != null) {
+                store.close();
+            }
+        }
+
+    }
+
     private static void checkpoints(String[] args) throws IOException {
         if (args.length == 0) {
             System.out
Index: oak-segment/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileStore.java
===================================================================
--- oak-segment/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileStore.java	(revision 1726966)
+++ oak-segment/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileStore.java	(working copy)
@@ -233,6 +233,7 @@
         private boolean memoryMapping;
         private final LoggingGCMonitor gcMonitor = new LoggingGCMonitor();
         private StatisticsProvider statsProvider = StatisticsProvider.NOOP;
+        private boolean readOnly = false;
 
         private Builder(File directory) {
             this.directory = directory;
@@ -325,6 +326,12 @@
             return this;
         }
 
+        @Nonnull
+        public Builder withReadOnly(boolean readOnly) {
+            this.readOnly = readOnly;
+            return this;
+        }
+
         /**
 
         /**
@@ -346,8 +353,7 @@
          */
         @Nonnull
         public FileStore create() throws IOException {
-            return new FileStore(
-                    blobStore, directory, root, maxFileSize, cacheSize, memoryMapping, gcMonitor, statsProvider, false);
+            return new FileStore(blobStore, directory, root, maxFileSize, cacheSize, memoryMapping, gcMonitor, statsProvider, readOnly);
         }
     }