SERVER-11051 Ignore non-existent databases reported by listDatabases in disk/preallocate.js

1 files changed, 7 insertions, 2 deletions

diff --git a/jstests/disk/preallocate.js b/jstests/disk/preallocate.js
index b1d98878ef5..f47c4915ab4 100644
--- a/jstests/disk/preallocate.js
+++ b/jstests/disk/preallocate.js
@@ -9,8 +9,13 @@ var m = startMongod( "--port", port, "--dbpath", "/data/db/" + baseName );
 var getTotalNonLocalSize = function() {
     var totalNonLocalDBSize = 0;
     m.getDBs().databases.forEach( function(dbStats) {
-            if (dbStats.name != "local")
-                totalNonLocalDBSize += dbStats.sizeOnDisk;
+        // We accept the local database's space overhead.
+        if (dbStats.name == "local") return;
+
+        // Databases with "sizeOnDisk=1" and "empty=true" dont' actually take up space o disk.
+        // See SERVER-11051.
+        if (dbStats.sizeOnDisk == 1 && dbStats.empty) return;
+        totalNonLocalDBSize += dbStats.sizeOnDisk;
     });
     return totalNonLocalDBSize;
 }