ndb -

  Unleash backup to write more than 32k at a time
  Using parameter BackupMaxWriteSize
  (greatly affect LCP time in 5.1, set default value to 256k)

ndb/include/mgmapi/mgmapi_config_parameters.h

@@ -65,6 +65,7 @@
 #define CFG_DB_BACKUP_DATA_BUFFER_MEM     134
 #define CFG_DB_BACKUP_LOG_BUFFER_MEM      135
 #define CFG_DB_BACKUP_WRITE_SIZE          136
+#define CFG_DB_BACKUP_MAX_WRITE_SIZE      139
 
 #define CFG_LOG_DESTINATION           147
 

ndb/src/kernel/blocks/backup/BackupInit.cpp

@@ -66,15 +66,16 @@ Backup::Backup(const Configuration & conf) :
 
   Uint32 szDataBuf = (2 * 1024 * 1024);
   Uint32 szLogBuf = (2 * 1024 * 1024);
-  Uint32 szWrite = 32768;
+  Uint32 szWrite = 32768, maxWriteSize = (256 * 1024);
   ndb_mgm_get_int_parameter(p, CFG_DB_BACKUP_DATA_BUFFER_MEM, &szDataBuf);
   ndb_mgm_get_int_parameter(p, CFG_DB_BACKUP_LOG_BUFFER_MEM, &szLogBuf);
   ndb_mgm_get_int_parameter(p, CFG_DB_BACKUP_WRITE_SIZE, &szWrite);
+  ndb_mgm_get_int_parameter(p, CFG_DB_BACKUP_MAX_WRITE_SIZE, &maxWriteSize);
   
   c_defaults.m_logBufferSize = szLogBuf;
   c_defaults.m_dataBufferSize = szDataBuf;
   c_defaults.m_minWriteSize = szWrite;
-  c_defaults.m_maxWriteSize = szWrite;
+  c_defaults.m_maxWriteSize = maxWriteSize;
   
   { // Init all tables
     ArrayList<Table> tables(c_tablePool);

ndb/src/mgmsrv/ConfigInfo.cpp

@@ -1191,7 +1191,19 @@ const ConfigInfo::ParamInfo ConfigInfo::m_ParamInfo[] = {
     false,
     ConfigInfo::CI_INT,
     "32K",
-    "0",
+    "2K",
+    STR_VALUE(MAX_INT_RNIL) },
+
+  { 
+    CFG_DB_BACKUP_MAX_WRITE_SIZE,
+    "BackupMaxWriteSize",
+    DB_TOKEN,
+    "Max size of filesystem writes made by backup (in bytes)",
+    ConfigInfo::CI_USED,
+    false,
+    ConfigInfo::CI_INT,
+    "256K",
+    "2K",
     STR_VALUE(MAX_INT_RNIL) },
 
   /***************************************************************************