diff --git a/deps/rocksdb b/deps/rocksdb
index c3034fce3..e3169e3ea 160000
--- a/deps/rocksdb
+++ b/deps/rocksdb
@@ -1 +1 @@
-Subproject commit c3034fce329017036c807e01261729bfc11a5d62
+Subproject commit e3169e3ea8762d2f34880742106858a23c8dc8b7
diff --git a/src/config.cpp b/src/config.cpp
index 6147bc429..794d65ee0 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -2852,6 +2852,7 @@ standardConfig configs[] = {
     createULongConfig("loading-process-events-interval-bytes", NULL, MODIFIABLE_CONFIG, 0, LONG_MAX, g_pserver->loading_process_events_interval_bytes, 2*1024*1024, MEMORY_CONFIG, NULL, NULL),
     createBoolConfig("multi-master-no-forward", NULL, MODIFIABLE_CONFIG, cserver.multimaster_no_forward, 0, validateMultiMasterNoForward, NULL),
     createBoolConfig("allow-write-during-load", NULL, MODIFIABLE_CONFIG, g_pserver->fWriteDuringActiveLoad, 0, NULL, NULL),
+    createBoolConfig("force-backlog-disk-reserve", NULL, MODIFIABLE_CONFIG, cserver.force_backlog_disk, 0, NULL, NULL),
 
 #ifdef USE_OPENSSL
     createIntConfig("tls-port", NULL, MODIFIABLE_CONFIG, 0, 65535, g_pserver->tls_port, 0, INTEGER_CONFIG, NULL, updateTLSPort), /* TCP port. */
diff --git a/src/replication.cpp b/src/replication.cpp
index d64bec35f..27f5af503 100644
--- a/src/replication.cpp
+++ b/src/replication.cpp
@@ -220,7 +220,12 @@ void createReplicationBacklog(void) {
             serverLog(LL_WARNING, "Failed to create disk backlog, will use memory only");
         }
     }
-    g_pserver->repl_backlog = (char*)zmalloc(g_pserver->repl_backlog_size, MALLOC_LOCAL);
+    if (cserver.force_backlog_disk && g_pserver->repl_backlog_disk != nullptr) {
+        g_pserver->repl_backlog = g_pserver->repl_backlog_disk;
+        g_pserver->repl_backlog_size = cserver.repl_backlog_disk_size;
+    } else {
+        g_pserver->repl_backlog = (char*)zmalloc(g_pserver->repl_backlog_size, MALLOC_LOCAL);
+    }
     g_pserver->repl_backlog_histlen = 0;
     g_pserver->repl_backlog_idx = 0;
     g_pserver->repl_backlog_start = g_pserver->master_repl_offset;
@@ -272,7 +277,7 @@ void resizeReplicationBacklog(long long newsize) {
             newsize = std::max(newsize, g_pserver->master_repl_offset - earliest_off);
             
             if (cserver.repl_backlog_disk_size != 0) {
-                if (newsize > g_pserver->repl_backlog_config_size) {
+                if (newsize > g_pserver->repl_backlog_config_size || cserver.force_backlog_disk) {
                     if (g_pserver->repl_backlog == g_pserver->repl_backlog_disk)
                         return; // Can't do anything more
                     serverLog(LL_NOTICE, "Switching to disk backed replication backlog due to exceeding memory limits");
@@ -5718,6 +5723,8 @@ void trimReplicationBacklog() {
         return; // We're already a good size
     if (g_pserver->repl_lowest_off > 0 && (g_pserver->master_repl_offset - g_pserver->repl_lowest_off + 1) > g_pserver->repl_backlog_config_size)
         return; // There is untransmitted data we can't truncate
+    if (cserver.force_backlog_disk && g_pserver->repl_backlog == g_pserver->repl_backlog_disk)
+        return; // We're already in the disk backlog and we're told to stay there
 
     serverLog(LL_NOTICE, "Reclaiming %lld replication backlog bytes", g_pserver->repl_backlog_size - g_pserver->repl_backlog_config_size);
     resizeReplicationBacklog(g_pserver->repl_backlog_config_size);
diff --git a/src/server.h b/src/server.h
index 466221f61..31cf398d0 100644
--- a/src/server.h
+++ b/src/server.h
@@ -2178,6 +2178,7 @@ struct redisServerConst {
     int fForkBgSave = false;
     int time_thread_priority = false;
     long long repl_backlog_disk_size = 0;
+    int force_backlog_disk = 0;
 };
 
 struct redisServer {