diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
index c813d2b582..a60c552c25 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
@@ -62,6 +62,7 @@ abstract class AbstractElasticIndex<K, V> implements Index<K, V> {
   private final Schema<V> schema;
   private final FillArgs fillArgs;
   private final SitePaths sitePaths;
+  private final String indexNameRaw;
 
   protected final String indexName;
   protected final JestHttpClient client;
@@ -82,10 +83,11 @@ abstract class AbstractElasticIndex<K, V> implements Index<K, V> {
     this.queryBuilder = new ElasticQueryBuilder();
     this.indexName =
         String.format(
-            "%s%s%04d",
+            "%s%s_%04d",
             Strings.nullToEmpty(cfg.getString("elasticsearch", null, "prefix")),
             indexName,
             schema.getVersion());
+    this.indexNameRaw = indexName;
     this.client = clientBuilder.build();
   }
 
@@ -101,7 +103,7 @@ abstract class AbstractElasticIndex<K, V> implements Index<K, V> {
 
   @Override
   public void markReady(boolean ready) throws IOException {
-    IndexUtils.setReady(sitePaths, indexName, schema.getVersion(), ready);
+    IndexUtils.setReady(sitePaths, indexNameRaw, schema.getVersion(), ready);
   }
 
   @Override
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
index 2a46c40954..f0766bca04 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
@@ -84,7 +84,7 @@ public class ElasticAccountIndex extends AbstractElasticIndex<Account.Id, Accoun
       JestClientBuilder clientBuilder,
       @Assisted Schema<AccountState> schema) {
     // No parts of FillArgs are currently required, just use null.
-    super(cfg, null, sitePaths, schema, clientBuilder, ACCOUNTS_PREFIX);
+    super(cfg, null, sitePaths, schema, clientBuilder, ACCOUNTS);
     this.accountCache = accountCache;
     this.mapping = new AccountMapping(schema);
   }
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
index 15185a1e92..9692358e96 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
@@ -109,7 +109,7 @@ class ElasticChangeIndex extends AbstractElasticIndex<Change.Id, ChangeData>
       SitePaths sitePaths,
       JestClientBuilder clientBuilder,
       @Assisted Schema<ChangeData> schema) {
-    super(cfg, fillArgs, sitePaths, schema, clientBuilder, CHANGES_PREFIX);
+    super(cfg, fillArgs, sitePaths, schema, clientBuilder, CHANGES);
     this.db = db;
     this.changeDataFactory = changeDataFactory;
     mapping = new ChangeMapping(schema);
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
index e2c34f2bb3..01aa0aa25f 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
@@ -81,7 +81,7 @@ public class ElasticGroupIndex extends AbstractElasticIndex<AccountGroup.UUID, A
       JestClientBuilder clientBuilder,
       @Assisted Schema<AccountGroup> schema) {
     // No parts of FillArgs are currently required, just use null.
-    super(cfg, null, sitePaths, schema, clientBuilder, GROUPS_PREFIX);
+    super(cfg, null, sitePaths, schema, clientBuilder, GROUPS);
     this.groupCache = groupCache;
     this.mapping = new GroupMapping(schema);
   }
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersionManager.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersionManager.java
index 74a6b69c0d..91c1becb74 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersionManager.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersionManager.java
@@ -51,20 +51,10 @@ public class ElasticVersionManager extends AbstractVersionManager implements Lif
     prefix = MoreObjects.firstNonNull(cfg.getString("index", null, "prefix"), "gerrit");
   }
 
-  @Override
-  protected <V> boolean isDirty(Collection<Version<V>> inUse, Version<V> v) {
-    return !inUse.contains(v);
-  }
-
   @Override
   protected <K, V, I extends Index<K, V>> TreeMap<Integer, Version<V>> scanVersions(
       IndexDefinition<K, V, I> def, GerritIndexStatus cfg) {
     TreeMap<Integer, Version<V>> versions = new TreeMap<>();
-    for (Schema<V> schema : def.getSchemas().values()) {
-      int v = schema.getVersion();
-      versions.put(v, new Version<>(schema, v, cfg.getReady(def.getName(), v)));
-    }
-
     try {
       for (String version : versionDiscovery.discover(prefix, def.getName())) {
         Integer v = Ints.tryParse(version);
@@ -72,13 +62,17 @@ public class ElasticVersionManager extends AbstractVersionManager implements Lif
           log.warn("Unrecognized version in index {}: {}", def.getName(), version);
           continue;
         }
-        if (!versions.containsKey(v)) {
-          versions.put(v, new Version<V>(null, v, cfg.getReady(def.getName(), v)));
-        }
+        versions.put(v, new Version<V>(null, v, true, cfg.getReady(def.getName(), v)));
       }
     } catch (IOException e) {
       log.error("Error scanning index: " + def.getName(), e);
     }
+
+    for (Schema<V> schema : def.getSchemas().values()) {
+      int v = schema.getVersion();
+      boolean exists = versions.containsKey(v);
+      versions.put(v, new Version<>(schema, v, exists, cfg.getReady(def.getName(), v)));
+    }
     return versions;
   }
 }
diff --git a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneVersionManager.java b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneVersionManager.java
index 04d7d3552d..441a4b77b9 100644
--- a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneVersionManager.java
+++ b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneVersionManager.java
@@ -39,15 +39,6 @@ import org.slf4j.LoggerFactory;
 public class LuceneVersionManager extends AbstractVersionManager implements LifecycleListener {
   private static final Logger log = LoggerFactory.getLogger(LuceneVersionManager.class);
 
-  private static class Version<V> extends AbstractVersionManager.Version<V> {
-    private final boolean exists;
-
-    private Version(Schema<V> schema, int version, boolean exists, boolean ready) {
-      super(schema, version, ready);
-      this.exists = exists;
-    }
-  }
-
   static Path getDir(SitePaths sitePaths, String prefix, Schema<?> schema) {
     return sitePaths.index_dir.resolve(String.format("%s%04d", prefix, schema.getVersion()));
   }
@@ -60,13 +51,6 @@ public class LuceneVersionManager extends AbstractVersionManager implements Life
     super(cfg, sitePaths, defs);
   }
 
-  @Override
-  protected <V> boolean isDirty(
-      Collection<com.google.gerrit.server.index.AbstractVersionManager.Version<V>> inUse,
-      com.google.gerrit.server.index.AbstractVersionManager.Version<V> v) {
-    return !inUse.contains(v) && ((Version<V>) v).exists;
-  }
-
   @Override
   protected <K, V, I extends Index<K, V>>
       TreeMap<Integer, AbstractVersionManager.Version<V>> scanVersions(
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/index/AbstractVersionManager.java b/gerrit-server/src/main/java/com/google/gerrit/server/index/AbstractVersionManager.java
index 33cca1e160..a0273ce220 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/index/AbstractVersionManager.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/index/AbstractVersionManager.java
@@ -35,12 +35,14 @@ public abstract class AbstractVersionManager implements LifecycleListener {
   public static class Version<V> {
     public final Schema<V> schema;
     public final int version;
+    public final boolean exists;
     public final boolean ready;
 
-    public Version(Schema<V> schema, int version, boolean ready) {
+    public Version(Schema<V> schema, int version, boolean exists, boolean ready) {
       checkArgument(schema == null || schema.getVersion() == version);
       this.schema = schema;
       this.version = version;
+      this.exists = exists;
       this.ready = ready;
     }
   }
@@ -179,11 +181,13 @@ public abstract class AbstractVersionManager implements LifecycleListener {
     }
   }
 
-  protected abstract <V> boolean isDirty(Collection<Version<V>> inUse, Version<V> v);
-
   protected abstract <K, V, I extends Index<K, V>> TreeMap<Integer, Version<V>> scanVersions(
       IndexDefinition<K, V, I> def, GerritIndexStatus cfg);
 
+  private <V> boolean isDirty(Collection<Version<V>> inUse, Version<V> v) {
+    return !inUse.contains(v) && v.exists;
+  }
+
   private boolean isLatestIndexVersion(String name, OnlineReindexer<?, ?, ?> reindexer) {
     int readVersion = defs.get(name).getIndexCollection().getSearchIndex().getSchema().getVersion();
     return reindexer == null || reindexer.getVersion() == readVersion;