diff --git a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java
index fad5c2f2b1..ef2ef91784 100644
--- a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java
+++ b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java
@@ -120,7 +120,6 @@ public class LuceneChangeIndex implements ChangeIndex, LifecycleListener {
   private final Schema<ChangeData> schema;
   private final SubIndex openIndex;
   private final SubIndex closedIndex;
-  private final boolean readOnly;
 
   LuceneChangeIndex(@GerritServerConfig Config cfg,
       SitePaths sitePaths,
@@ -128,15 +127,19 @@ public class LuceneChangeIndex implements ChangeIndex, LifecycleListener {
       @IndexExecutor ListeningScheduledExecutorService executor,
       FillArgs fillArgs,
       Schema<ChangeData> schema,
-      boolean readOnly) throws IOException {
+      String base) throws IOException {
     this.indexes = indexes;
     this.sitePaths = sitePaths;
     this.fillArgs = fillArgs;
     this.executor = executor;
     this.schema = schema;
-    this.readOnly = readOnly;
 
-    File dir = new File(sitePaths.index_dir, "changes_" + schema.getVersion());
+    File dir;
+    if (base == null) {
+      dir = new File(sitePaths.index_dir, "changes_" + schema.getVersion());
+    } else {
+      dir = new File(base);
+    }
     openIndex = new SubIndex(new File(dir, CHANGES_OPEN),
         getIndexWriterConfig(cfg, "changes_open"));
     closedIndex = new SubIndex(new File(dir, CHANGES_CLOSED),
@@ -179,10 +182,6 @@ public class LuceneChangeIndex implements ChangeIndex, LifecycleListener {
   public ListenableFuture<Void> insert(ChangeData cd) throws IOException {
     Term id = QueryBuilder.idTerm(cd);
     Document doc = toDocument(cd);
-    if (readOnly) {
-      return Futures.immediateFuture(null);
-    }
-
     if (cd.getChange().getStatus().isOpen()) {
       return allOf(
           closedIndex.delete(id),
@@ -199,9 +198,6 @@ public class LuceneChangeIndex implements ChangeIndex, LifecycleListener {
   public ListenableFuture<Void> replace(ChangeData cd) throws IOException {
     Term id = QueryBuilder.idTerm(cd);
     Document doc = toDocument(cd);
-    if (readOnly) {
-      return Futures.immediateFuture(null);
-    }
     if (cd.getChange().getStatus().isOpen()) {
       return allOf(
           closedIndex.delete(id),
@@ -217,9 +213,6 @@ public class LuceneChangeIndex implements ChangeIndex, LifecycleListener {
   @Override
   public ListenableFuture<Void> delete(ChangeData cd) throws IOException {
     Term id = QueryBuilder.idTerm(cd);
-    if (readOnly) {
-      return Futures.immediateFuture(null);
-    }
     return allOf(
         openIndex.delete(id),
         closedIndex.delete(id));
diff --git a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneIndexModule.java b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneIndexModule.java
index fe3b3c82df..a302f6fa0f 100644
--- a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneIndexModule.java
+++ b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneIndexModule.java
@@ -34,17 +34,17 @@ import java.io.IOException;
 public class LuceneIndexModule extends LifecycleModule {
   private final boolean checkVersion;
   private final int threads;
-  private final boolean readOnly;
+  private final String base;
 
   public LuceneIndexModule() {
-    this(true, 0, false);
+    this(true, 0, null);
   }
 
   public LuceneIndexModule(boolean checkVersion, int threads,
-      boolean readOnly) {
+      String base) {
     this.checkVersion = checkVersion;
     this.threads = threads;
-    this.readOnly = readOnly;
+    this.base = base;
   }
 
   @Override
@@ -65,6 +65,6 @@ public class LuceneIndexModule extends LifecycleModule {
       @IndexExecutor ListeningScheduledExecutorService executor,
       FillArgs fillArgs) throws IOException {
     return new LuceneChangeIndex(cfg, sitePaths, indexes, executor, fillArgs,
-        ChangeSchemas.getLatestRelease(), readOnly);
+        ChangeSchemas.getLatestRelease(), base);
   }
 }
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Reindex.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Reindex.java
index 3c5b0ab70d..1070a52200 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Reindex.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Reindex.java
@@ -98,8 +98,8 @@ public class Reindex extends SiteProgram {
   @Option(name = "--threads", usage = "Number of threads to use for indexing")
   private int threads = Runtime.getRuntime().availableProcessors();
 
-  @Option(name = "--dry-run", usage = "Dry run: don't write anything to index")
-  private boolean dryRun;
+  @Option(name = "--output", usage = "Prefix for output; path for local disk index, or prefix for remote index")
+  private String outputBase;
 
   @Option(name = "--verbose", usage = "Output debug information for each change")
   private boolean verbose;
@@ -142,10 +142,10 @@ public class Reindex extends SiteProgram {
     AbstractModule changeIndexModule;
     switch (IndexModule.getIndexType(dbInjector)) {
       case LUCENE:
-        changeIndexModule = new LuceneIndexModule(false, threads, dryRun);
+        changeIndexModule = new LuceneIndexModule(false, threads, outputBase);
         break;
       case SOLR:
-        changeIndexModule = new SolrIndexModule(false, threads);
+        changeIndexModule = new SolrIndexModule(false, threads, outputBase);
         break;
       default:
         changeIndexModule = new NoIndexModule();
@@ -208,9 +208,6 @@ public class Reindex extends SiteProgram {
   }
 
   private void deleteAll() throws IOException {
-    if (dryRun) {
-      return;
-    }
     ChangeIndex index = sysInjector.getInstance(ChangeIndex.class);
     index.deleteAll();
   }
@@ -470,9 +467,6 @@ public class Reindex extends SiteProgram {
 
   private void writeVersion() throws IOException,
       ConfigInvalidException {
-    if (dryRun) {
-      return;
-    }
     ChangeIndex index = sysInjector.getInstance(ChangeIndex.class);
     index.finishIndex();
   }
diff --git a/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrChangeIndex.java b/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrChangeIndex.java
index cdb5a9c294..b338dffbe3 100644
--- a/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrChangeIndex.java
+++ b/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrChangeIndex.java
@@ -43,7 +43,6 @@ import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gerrit.server.query.change.ChangeDataSource;
 import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.ResultSet;
-import com.google.inject.Singleton;
 
 import org.apache.lucene.search.Query;
 import org.apache.solr.client.solrj.SolrQuery;
@@ -67,7 +66,6 @@ import java.util.Map;
 import java.util.Set;
 
 /** Secondary index implementation using a remote Solr instance. */
-@Singleton
 class SolrChangeIndex implements ChangeIndex, LifecycleListener {
   public static final String CHANGES_OPEN = "changes_open";
   public static final String CHANGES_CLOSED = "changes_closed";
@@ -85,7 +83,8 @@ class SolrChangeIndex implements ChangeIndex, LifecycleListener {
       FillArgs fillArgs,
       SitePaths sitePaths,
       IndexCollection indexes,
-      Schema<ChangeData> schema) throws IOException {
+      Schema<ChangeData> schema,
+      String base) throws IOException {
     this.fillArgs = fillArgs;
     this.sitePaths = sitePaths;
     this.indexes = indexes;
@@ -96,11 +95,12 @@ class SolrChangeIndex implements ChangeIndex, LifecycleListener {
       throw new IllegalStateException("index.solr.url must be supplied");
     }
 
+    base = Strings.nullToEmpty(base);
     openIndex = new CloudSolrServer(url);
-    openIndex.setDefaultCollection(CHANGES_OPEN);
+    openIndex.setDefaultCollection(base + CHANGES_OPEN);
 
     closedIndex = new CloudSolrServer(url);
-    closedIndex.setDefaultCollection(CHANGES_CLOSED);
+    closedIndex.setDefaultCollection(base + CHANGES_CLOSED);
   }
 
   @Override
diff --git a/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrIndexModule.java b/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrIndexModule.java
index d05fd5b059..4b892a8b43 100644
--- a/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrIndexModule.java
+++ b/gerrit-solr/src/main/java/com/google/gerrit/solr/SolrIndexModule.java
@@ -32,14 +32,16 @@ import java.io.IOException;
 public class SolrIndexModule extends LifecycleModule {
   private final boolean checkVersion;
   private final int threads;
+  private final String base;
 
   public SolrIndexModule() {
-    this(true, 0);
+    this(true, 0, null);
   }
 
-  public SolrIndexModule(boolean checkVersion, int threads) {
+  public SolrIndexModule(boolean checkVersion, int threads, String base) {
     this.checkVersion = checkVersion;
     this.threads = threads;
+    this.base = base;
   }
 
   @Override
@@ -59,6 +61,6 @@ public class SolrIndexModule extends LifecycleModule {
       IndexCollection indexes,
       FillArgs fillArgs) throws IOException {
     return new SolrChangeIndex(cfg, fillArgs, sitePaths, indexes,
-        ChangeSchemas.getLatestRelease());
+        ChangeSchemas.getLatestRelease(), base);
   }
 }