diff --git a/include/iscsi-private.h b/include/iscsi-private.h
index ddf7807..528b9a1 100644
--- a/include/iscsi-private.h
+++ b/include/iscsi-private.h
@@ -215,11 +215,21 @@ void iscsi_free_scsi_cbdata(struct iscsi_context *iscsi, struct iscsi_scsi_cbdat
 struct iscsi_pdu *iscsi_allocate_pdu(struct iscsi_context *iscsi,
 				     enum iscsi_opcode opcode,
 				     enum iscsi_opcode response_opcode);
+struct iscsi_pdu *iscsi_allocate_pdu_size(struct iscsi_context *iscsi,
+				     enum iscsi_opcode opcode,
+				     enum iscsi_opcode response_opcode,
+				     size_t payload_size);
 struct iscsi_pdu *iscsi_allocate_pdu_with_itt_flags(struct iscsi_context *iscsi,
        		 		enum iscsi_opcode opcode,
 				enum iscsi_opcode response_opcode,
 				uint32_t itt,
 				uint32_t flags);
+struct iscsi_pdu *iscsi_allocate_pdu_with_itt_flags_size(struct iscsi_context *iscsi,
+       		 		enum iscsi_opcode opcode,
+				enum iscsi_opcode response_opcode,
+				uint32_t itt,
+				uint32_t flags,
+				size_t payload_size);
 void iscsi_free_pdu(struct iscsi_context *iscsi, struct iscsi_pdu *pdu);
 void iscsi_pdu_set_pduflags(struct iscsi_pdu *pdu, unsigned char flags);
 void iscsi_pdu_set_immediate(struct iscsi_pdu *pdu);
diff --git a/include/iscsi.h b/include/iscsi.h
index 9753d22..6ac7f0e 100644
--- a/include/iscsi.h
+++ b/include/iscsi.h
@@ -33,7 +33,6 @@ struct iscsi_context;
 struct sockaddr;
 
 #define MAX_STRING_SIZE (255)
-#define PAGE_SIZE (4096)
 
 /*
  * Syntax for normal and portal/discovery URLs.
diff --git a/lib/login.c b/lib/login.c
index 04368d2..5728007 100644
--- a/lib/login.c
+++ b/lib/login.c
@@ -735,10 +735,10 @@ iscsi_login_async(struct iscsi_context *iscsi, iscsi_command_cb cb,
 		return -1;
 	}
 
-	pdu = iscsi_allocate_pdu_with_itt_flags(iscsi,
+	pdu = iscsi_allocate_pdu_with_itt_flags_size(iscsi,
 				ISCSI_PDU_LOGIN_REQUEST,
 				ISCSI_PDU_LOGIN_RESPONSE,
-				iscsi->itt, 0);
+				iscsi->itt, 0, 1024);
 	if (pdu == NULL) {
 		iscsi_set_error(iscsi, "Out-of-memory: Failed to allocate "
 				"login pdu.");
diff --git a/lib/pdu.c b/lib/pdu.c
index 86dc2b1..f2e11ba 100644
--- a/lib/pdu.c
+++ b/lib/pdu.c
@@ -31,8 +31,8 @@
 #include "slist.h"
 
 struct iscsi_pdu *
-iscsi_allocate_pdu_with_itt_flags(struct iscsi_context *iscsi, enum iscsi_opcode opcode,
-				  enum iscsi_opcode response_opcode, uint32_t itt, uint32_t flags)
+iscsi_allocate_pdu_with_itt_flags_size(struct iscsi_context *iscsi, enum iscsi_opcode opcode,
+				  enum iscsi_opcode response_opcode, uint32_t itt, uint32_t flags, size_t payload_size)
 {
 	struct iscsi_pdu *pdu;
 
@@ -43,7 +43,10 @@ iscsi_allocate_pdu_with_itt_flags(struct iscsi_context *iscsi, enum iscsi_opcode
 	}
 
 	pdu->outdata.size = ISCSI_HEADER_SIZE;
-	pdu->outdata.data = iscsi_zmalloc(iscsi, pdu->outdata.size);
+	pdu->outdata.alloc_size = 64;
+	while (pdu->outdata.alloc_size < ISCSI_HEADER_SIZE+payload_size) pdu->outdata.alloc_size<<=1;
+	pdu->outdata.data = iscsi_malloc(iscsi, pdu->outdata.alloc_size);
+	memset(pdu->outdata.data, 0, ISCSI_HEADER_SIZE);
 
 	if (pdu->outdata.data == NULL) {
 		iscsi_set_error(iscsi, "failed to allocate pdu header");
@@ -70,6 +73,13 @@ iscsi_allocate_pdu_with_itt_flags(struct iscsi_context *iscsi, enum iscsi_opcode
 	return pdu;
 }
 
+struct iscsi_pdu *
+iscsi_allocate_pdu_with_itt_flags(struct iscsi_context *iscsi, enum iscsi_opcode opcode,
+				  enum iscsi_opcode response_opcode, uint32_t itt, uint32_t flags)
+{
+	return iscsi_allocate_pdu_with_itt_flags_size(iscsi, opcode, response_opcode, itt, flags, 0);
+}
+
 struct iscsi_pdu *
 iscsi_allocate_pdu(struct iscsi_context *iscsi, enum iscsi_opcode opcode,
 		   enum iscsi_opcode response_opcode)
@@ -77,6 +87,13 @@ iscsi_allocate_pdu(struct iscsi_context *iscsi, enum iscsi_opcode opcode,
 	return iscsi_allocate_pdu_with_itt_flags(iscsi, opcode, response_opcode, iscsi->itt++, 0);
 }	
 
+struct iscsi_pdu *
+iscsi_allocate_pdu_size(struct iscsi_context *iscsi, enum iscsi_opcode opcode,
+		   enum iscsi_opcode response_opcode, size_t payload_size)
+{
+	return iscsi_allocate_pdu_with_itt_flags_size(iscsi, opcode, response_opcode, iscsi->itt++, 0, payload_size);
+}	
+
 
 
 void
@@ -120,18 +137,20 @@ iscsi_add_data(struct iscsi_context *iscsi, struct iscsi_data *data,
 		aligned = (aligned+3)&0xfffffffc;
 	}
 
-	int new_alloc_size=data->alloc_size;
-	if (new_alloc_size < PAGE_SIZE) new_alloc_size=PAGE_SIZE;
+	int new_alloc_size = data->alloc_size;
+	if (new_alloc_size < 64) new_alloc_size=64;
 	
 	while (aligned > new_alloc_size) new_alloc_size<<=1;
 
 	if (data->data != NULL && data->alloc_size == 0) data->alloc_size=data->size;
 	
-	if (data->alloc_size == 0)
+	if (data->alloc_size == 0) {
 		data->data = iscsi_malloc(iscsi, new_alloc_size);
+	}
 	else
-		if (data->alloc_size != new_alloc_size)
+		if (data->alloc_size != new_alloc_size) {
 			data->data = realloc(data->data, new_alloc_size);
+		}
 	
 	if (data->data == NULL) {
 		iscsi_set_error(iscsi, "failed to allocate buffer for %d "
diff --git a/lib/scsi-command.c b/lib/scsi-command.c
index f3f4cef..57c50d3 100644
--- a/lib/scsi-command.c
+++ b/lib/scsi-command.c
@@ -85,10 +85,11 @@ iscsi_send_data_out(struct iscsi_context *iscsi, struct iscsi_pdu *cmd_pdu,
 			len = iscsi->target_max_recv_data_segment_length;
 		}
 
-		pdu = iscsi_allocate_pdu_with_itt_flags(iscsi, ISCSI_PDU_DATA_OUT,
+		pdu = iscsi_allocate_pdu_with_itt_flags_size(iscsi, ISCSI_PDU_DATA_OUT,
 				 ISCSI_PDU_NO_PDU,
 				 cmd_pdu->itt,
-				 ISCSI_PDU_DELETE_WHEN_SENT|ISCSI_PDU_NO_CALLBACK);
+				 ISCSI_PDU_DELETE_WHEN_SENT|ISCSI_PDU_NO_CALLBACK,
+				 len);
 		if (pdu == NULL) {
 			iscsi_set_error(iscsi, "Out-of-memory, Failed to allocate "
 				"scsi data out pdu.");
@@ -198,8 +199,16 @@ iscsi_scsi_command_async(struct iscsi_context *iscsi, int lun,
 
 	scsi_set_task_private_ptr(task, scsi_cbdata);
 
-	pdu = iscsi_allocate_pdu(iscsi, ISCSI_PDU_SCSI_REQUEST,
-				 ISCSI_PDU_SCSI_RESPONSE);
+	u_int32_t payload_size = 0;
+	if (iscsi->use_immediate_data == ISCSI_IMMEDIATE_DATA_YES) {
+		payload_size=data.size;
+		if (payload_size > iscsi->first_burst_length) {
+				payload_size = iscsi->first_burst_length;
+		}
+	}
+
+	pdu = iscsi_allocate_pdu_size(iscsi, ISCSI_PDU_SCSI_REQUEST,
+				 ISCSI_PDU_SCSI_RESPONSE, payload_size);
 	if (pdu == NULL) {
 		iscsi_set_error(iscsi, "Out-of-memory, Failed to allocate "
 				"scsi pdu.");