A while back I tested NDS 7.0 with libdb43 while investigating some performance
issues, below are the minor changes I made to make it work plus a note about them:

BTW, some changes were necessary to run with db4.3 and maybe they will
apply when you upgrade to db4.4 too.  The changes implement some of the
API updates in libdb4.3 documented here.
    http://www.sleepycat.com/docs/ref/upgrade.4.3/intro.html
Note: The verbose logging fix is just to get it to compile, verbose
checkpointing will be broken.

Index: plugins/replication/cl5_api.c
===================================================================
RCS file:
/repository/source/ldap/ns/netsite/ldap/servers/plugins/replication/cl5_api.c,v
retrieving revision 1.1.1.5
diff -u -4 -r1.1.1.5 cl5_api.c
--- cl5_api.c    2005/03/17 22:13:22    1.1.1.5
+++ cl5_api.c    2005/07/05 20:55:15
@@ -321,9 +321,9 @@
 static int  _cl5UpdateRUV (Object *obj, CSN *csn, PRBool newReplica,
PRBool purge);
 static int  _cl5GetRUV2Purge2 (Object *fileObj, RUV **ruv);
 
 /* db error processing */
-static void _cl5DBLogPrint(const char* prefix, char *buffer);
+static void _cl5DBLogPrint(const DB_ENV *dbenv, const char* prefix,
const char *buffer);
 
 /* bakup/recovery, import/export */
 static PRBool _cl5IsLogFile (const char *name);
 static int _cl5Recover (int open_flags, DB_ENV *dbEnv);
@@ -341,9 +341,9 @@
 static Object* _cl5GetReplica (const slapi_operation_parameters *op,
const char* replGen);
 static int _cl5FileEndsWith(const char *filename, const char *ext);
 
 /* Callback function for libdb to spit error info into our log */
-static void dblayer_log_print(const char* prefix, char *buffer)
+static void dblayer_log_print(const DB_ENV *dbenv, const char* prefix,
const char *buffer)
 {
     /* We ignore the prefix since we know who we are anyway */
     slapi_log_error(SLAPI_LOG_REPL, repl_plugin_name_cl, "libdb: %s\n",
buffer);
 }
@@ -3697,9 +3697,8 @@
    
     if (s_cl5Desc.dbConfig.verbose)
     {
         int on = 1;
-        dbEnv->set_verbose(dbEnv, DB_VERB_CHKPOINT, on);
         dbEnv->set_verbose(dbEnv, DB_VERB_DEADLOCK, on);
         dbEnv->set_verbose(dbEnv, DB_VERB_RECOVERY, on);
         dbEnv->set_verbose(dbEnv, DB_VERB_WAITSFOR, on);
     }
@@ -3711,9 +3710,9 @@
         dbEnv->set_alloc(dbEnv, malloc, realloc, free);
 #endif
 }
 
-static void _cl5DBLogPrint(const char* prefix, char *buffer)
+static void _cl5DBLogPrint(const DB_ENV *dbenv, const char* prefix,
const char *buffer)
 {
     /* We ignore the prefix since we know who we are anyway */
     slapi_log_error (SLAPI_LOG_FATAL, repl_plugin_name_cl, "cl5: %s\n",
buffer);
 }
@@ -4451,9 +4450,9 @@
                             return CL5_SUCCESS;
 
         case DB_NOTFOUND:    file->entryCount = 0;
 #if 1000*DB_VERSION_MAJOR + 100*DB_VERSION_MINOR >= 3300
-                            rc = file->db->stat(file->db,
(void*)&stats, 0);
+                            rc = file->db->stat(file->db, NULL,
(void*)&stats, 0);
 #else
                             rc = file->db->stat(file->db,
(void*)&stats, malloc, 0);
 #endif
                             if (rc != 0)


Index: slapd/back-ldbm/dblayer.c
===================================================================
RCS file:
/repository/source/ldap/ns/netsite/ldap/servers/slapd/back-ldbm/dblayer.c,v
retrieving revision 1.1.1.8
diff -u -4 -r1.1.1.8 dblayer.c
--- dblayer.c    2005/03/17 22:14:08    1.1.1.8
+++ dblayer.c    2005/07/05 20:44:13
@@ -284,9 +284,9 @@
         pEnv->remove(pEnv, home_dir, DB_FORCE);
 }
 
 /* Callback function for libdb to spit error info into our log */
-static void dblayer_log_print(const char* prefix, char *buffer)
+static void dblayer_log_print(const DB_ENV *dbenv, const char* prefix,
const char *buffer)
 {
     /* We ignore the prefix since we know who we are anyway */
     LDAPDebug(LDAP_DEBUG_ANY,"libdb: %s\n", buffer, 0, 0);   
 }
@@ -359,8 +359,18 @@
 
     return (ret < 0) ? errno : 0;
 }
 
+/* Helper function for large seeks, db4.3 */
+static int dblayer_seek43_large(int fd, off64_t offset, int whence)
+{
+    int ret = 0;
+
+    ret = lseek64(fd, offset, whence);
+
+    return (ret < 0) ? errno : 0;
+}
+
 /* helper function for large fstat -- this depends on 'struct stat64'
having
  * the following members:
  *    off64_t        st_size;
  *      long        st_blksize;
@@ -423,9 +433,9 @@
     db_env_set_func_open((int (*)(const char *, int,
...))dblayer_open_large);
 #endif  /* !irix */
     db_env_set_func_ioinfo(dblayer_ioinfo_large);
     db_env_set_func_exists((int (*)())dblayer_exists_large);
-    db_env_set_func_seek((int (*)())dblayer_seek24_large);
+    db_env_set_func_seek((int (*)())dblayer_seek43_large);
 
     LDAPDebug(LDAP_DEBUG_TRACE, "Enabled 64-bit files\n", 0, 0, 0);
 #endif   /* DB_USE_64LFS */
     return 0;
@@ -611,9 +621,8 @@
     pEnv->set_lk_max_locks(pEnv, priv->dblayer_lock_config);
     pEnv->set_lk_max_objects(pEnv, priv->dblayer_lock_config);
     pEnv->set_lk_max_lockers(pEnv, priv->dblayer_lock_config);
     if (priv->dblayer_verbose) {
-        pEnv->set_verbose(pEnv, DB_VERB_CHKPOINT, 1);    /* 1 means on */
         pEnv->set_verbose(pEnv, DB_VERB_DEADLOCK, 1);    /* 1 means on */
         pEnv->set_verbose(pEnv, DB_VERB_RECOVERY, 1);    /* 1 means on */
         pEnv->set_verbose(pEnv, DB_VERB_WAITSFOR, 1);    /* 1 means on */
     }
 info: