diff --git a/src/aiori-HDF5.c b/src/aiori-HDF5.c
index 7649be0..808a7ea 100644
--- a/src/aiori-HDF5.c
+++ b/src/aiori-HDF5.c
@@ -98,6 +98,8 @@ static IOR_offset_t HDF5_GetFileSize(IOR_param_t *, MPI_Comm, char *);
 
 ior_aiori_t hdf5_aiori = {
         "HDF5",
+        NULL, /* no-op init, finalize */
+        NULL,
         HDF5_Create,
         HDF5_Open,
         HDF5_Xfer,
@@ -105,7 +107,9 @@ ior_aiori_t hdf5_aiori = {
         HDF5_Delete,
         HDF5_SetVersion,
         HDF5_Fsync,
-        HDF5_GetFileSize
+        HDF5_GetFileSize,
+        POSIX_Access,
+        POSIX_Mkdir
 };
 
 static hid_t xferPropList;      /* xfer property list */
diff --git a/src/aiori-MPIIO.c b/src/aiori-MPIIO.c
index 4920f6d..90758a8 100644
--- a/src/aiori-MPIIO.c
+++ b/src/aiori-MPIIO.c
@@ -46,6 +46,8 @@ static void MPIIO_Fsync(void *, IOR_param_t *);
 
 ior_aiori_t mpiio_aiori = {
         "MPIIO",
+        NULL, /* no-op init, finalize */
+        NULL,
         MPIIO_Create,
         MPIIO_Open,
         MPIIO_Xfer,
@@ -53,7 +55,9 @@ ior_aiori_t mpiio_aiori = {
         MPIIO_Delete,
         MPIIO_SetVersion,
         MPIIO_Fsync,
-        MPIIO_GetFileSize
+        MPIIO_GetFileSize,
+        POSIX_Access,
+        POSIX_Mkdir
 };
 
 /***************************** F U N C T I O N S ******************************/
diff --git a/src/aiori-NCMPI.c b/src/aiori-NCMPI.c
index e3e678f..7614b8f 100644
--- a/src/aiori-NCMPI.c
+++ b/src/aiori-NCMPI.c
@@ -62,6 +62,8 @@ static IOR_offset_t NCMPI_GetFileSize(IOR_param_t *, MPI_Comm, char *);
 
 ior_aiori_t ncmpi_aiori = {
         "NCMPI",
+        NULL, /* no-op init, finalize */
+        NULL,
         NCMPI_Create,
         NCMPI_Open,
         NCMPI_Xfer,
@@ -69,7 +71,9 @@ ior_aiori_t ncmpi_aiori = {
         NCMPI_Delete,
         NCMPI_SetVersion,
         NCMPI_Fsync,
-        NCMPI_GetFileSize
+        NCMPI_GetFileSize,
+        POSIX_Access,
+        POSIX_Mkdir
 };
 
 /***************************** F U N C T I O N S ******************************/
diff --git a/src/aiori-POSIX.c b/src/aiori-POSIX.c
index ca6065e..e6bf19a 100644
--- a/src/aiori-POSIX.c
+++ b/src/aiori-POSIX.c
@@ -70,6 +70,8 @@ static IOR_offset_t POSIX_GetFileSize(IOR_param_t *, MPI_Comm, char *);
 
 ior_aiori_t posix_aiori = {
         "POSIX",
+        NULL, /* no-op init, finalize */
+        NULL,
         POSIX_Create,
         POSIX_Open,
         POSIX_Xfer,
@@ -77,7 +79,9 @@ ior_aiori_t posix_aiori = {
         POSIX_Delete,
         POSIX_SetVersion,
         POSIX_Fsync,
-        POSIX_GetFileSize
+        POSIX_GetFileSize,
+        POSIX_Access,
+        POSIX_Mkdir
 };
 
 /***************************** F U N C T I O N S ******************************/
@@ -451,3 +455,11 @@ static IOR_offset_t POSIX_GetFileSize(IOR_param_t * test, MPI_Comm testComm,
 
         return (aggFileSizeFromStat);
 }
+
+int POSIX_Access(char *testFileName, int mode){
+        return access(testFileName, mode);
+}
+
+int POSIX_Mkdir(char *dir, int mode){
+        return mkdir(dir, mode);
+}
diff --git a/src/aiori.h b/src/aiori.h
index d88abbf..b2f7b52 100644
--- a/src/aiori.h
+++ b/src/aiori.h
@@ -51,6 +51,10 @@
 
 typedef struct ior_aiori {
         char *name;
+        /* init and finalizes should be called exactly once during a program
+         * run */
+        void (*init)(IOR_param_t *);
+        void (*finalize)(IOR_param_t *);
         void *(*create)(char *, IOR_param_t *);
         void *(*open)(char *, IOR_param_t *);
         IOR_offset_t (*xfer)(int, void *, IOR_size_t *,
@@ -60,6 +64,10 @@ typedef struct ior_aiori {
         void (*set_version)(IOR_param_t *);
         void (*fsync)(void *, IOR_param_t *);
         IOR_offset_t (*get_file_size)(IOR_param_t *, MPI_Comm, char *);
+        /* these functions are expected to behave identically to their POSIX
+         * equivalents */
+        int  (*access)(char *, int mode);
+        int  (*mkdir)(char *, int mode);
 } ior_aiori_t;
 
 ior_aiori_t posix_aiori;
@@ -70,4 +78,7 @@ ior_aiori_t ncmpi_aiori;
 IOR_offset_t MPIIO_GetFileSize(IOR_param_t * test, MPI_Comm testComm,
                                char *testFileName);
 
+int POSIX_Access(char *testFileName, int mode);
+int POSIX_Mkdir(char *dir, int mode);
+
 #endif /* not _AIORI_H */
diff --git a/src/ior.c b/src/ior.c
index 163a59c..de51c0e 100644
--- a/src/ior.c
+++ b/src/ior.c
@@ -1083,14 +1083,15 @@ static char *PrependDir(IOR_param_t * test, char *rootDir)
         sprintf(dir, "%s%d", dir, (rank + rankOffset) % test->numTasks);
 
         /* dir doesn't exist, so create */
-        if (access(dir, F_OK) != 0) {
-                if (mkdir(dir, S_IRWXU) < 0) {
+        if (backend->access(dir, F_OK) != 0) {
+                if (backend->mkdir(dir, S_IRWXU) < 0) {
                         ERR("cannot create directory");
                 }
 
                 /* check if correct permissions */
-        } else if (access(dir, R_OK) != 0 || access(dir, W_OK) != 0 ||
-                   access(dir, X_OK) != 0) {
+        } else if (backend->access(dir, R_OK) != 0 ||
+                   backend->access(dir, W_OK) != 0 ||
+                   backend->access(dir, X_OK) != 0) {
                 ERR("invalid directory permissions");
         }
 
@@ -1261,7 +1262,7 @@ static void RemoveFile(char *testFileName, int filePerProc, IOR_param_t * test)
                         rankOffset = 0;
                         GetTestFileName(testFileName, test);
                 }
-                if (access(testFileName, F_OK) == 0) {
+                if (backend->access(testFileName, F_OK) == 0) {
                         backend->delete(testFileName, test);
                 }
                 if (test->reorderTasksRandom == TRUE) {
@@ -1269,7 +1270,7 @@ static void RemoveFile(char *testFileName, int filePerProc, IOR_param_t * test)
                         GetTestFileName(testFileName, test);
                 }
         } else {
-                if ((rank == 0) && (access(testFileName, F_OK) == 0)) {
+                if ((rank == 0) && (backend->access(testFileName, F_OK) == 0)) {
                         backend->delete(testFileName, test);
                 }
         }
@@ -1971,6 +1972,10 @@ static void TestIoSys(IOR_test_t *test)
 
         hog_buf = HogMemory(params);
 
+        /* do backend-specific initialization */
+        if (backend->init)
+                backend->init(params);
+
         startTime = GetTimeStamp();
 
         /* loop over test iterations */
@@ -2228,6 +2233,10 @@ static void TestIoSys(IOR_test_t *test)
                 rankOffset = 0;
         }
 
+        /* do backend-specific finalization */
+        if (backend->finalize)
+                backend->finalize(params);
+
         MPI_CHECK(MPI_Comm_free(&testComm), "MPI_Comm_free() error");
 
         if (params->summary_every_test) {