diff --git a/Makefile b/Makefile
index b4e91ede9..db82951e5 100644
--- a/Makefile
+++ b/Makefile
@@ -98,7 +98,7 @@ install:
 uninstall: 
 	cd $(SCST_DIR) && $(MAKE) $@
 	@if [ -d $(QLA_DIR) ]; then cd $(QLA_DIR) && $(MAKE) $@; fi
-	@if [ -d $(LSI_DIR) ]; then cd $(LSI_DIR) && $(MAKE) $@; fi
+#	@if [ -d $(LSI_DIR) ]; then cd $(LSI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(SRP_DIR) ]; then cd $(SRP_DIR) && $(MAKE) $@; fi
 	@if [ -d $(ISCSI_DIR) ]; then cd $(ISCSI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(USR_DIR) ]; then cd $(USR_DIR) && $(MAKE) $@; fi
@@ -107,7 +107,7 @@ clean:
 	cd $(SCST_DIR) && $(MAKE) $@
 	@if [ -d $(QLA_INI_DIR) ]; then cd $(QLA_INI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(QLA_DIR) ]; then cd $(QLA_DIR) && $(MAKE) $@; fi
-	@if [ -d $(LSI_DIR) ]; then cd $(LSI_DIR) && $(MAKE) $@; fi
+#	@if [ -d $(LSI_DIR) ]; then cd $(LSI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(SRP_DIR) ]; then cd $(SRP_DIR) && $(MAKE) $@; fi
 	@if [ -d $(ISCSI_DIR) ]; then cd $(ISCSI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(USR_DIR) ]; then cd $(USR_DIR) && $(MAKE) $@; fi
@@ -116,7 +116,7 @@ extraclean:
 	cd $(SCST_DIR) && $(MAKE) $@
 	@if [ -d $(QLA_INI_DIR) ]; then cd $(QLA_INI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(QLA_DIR) ]; then cd $(QLA_DIR) && $(MAKE) $@; fi
-	@if [ -d $(LSI_DIR) ]; then cd $(LSI_DIR) && $(MAKE) $@; fi
+#	@if [ -d $(LSI_DIR) ]; then cd $(LSI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(SRP_DIR) ]; then cd $(SRP_DIR) && $(MAKE) $@; fi
 	@if [ -d $(ISCSI_DIR) ]; then cd $(ISCSI_DIR) && $(MAKE) $@; fi
 	@if [ -d $(USR_DIR) ]; then cd $(USR_DIR) && $(MAKE) $@; fi
diff --git a/iscsi-scst/include/iscsi_scst.h b/iscsi-scst/include/iscsi_scst.h
index 242ad07b8..04d03ce1b 100644
--- a/iscsi-scst/include/iscsi_scst.h
+++ b/iscsi-scst/include/iscsi_scst.h
@@ -119,15 +119,18 @@ struct iscsi_event {
 	u32 state;
 };
 
+struct iscsi_register_info {
+	aligned_u64 version;
+	u32 max_data_seg_len;
+};
+
 #define	DEFAULT_NR_QUEUED_CMNDS	32
 #define	MIN_NR_QUEUED_CMNDS	1
 #define	MAX_NR_QUEUED_CMNDS	256
 
-#define MAX_DATA_SEG_LEN	(4096/sizeof(struct iovec)*4096)
-
 #define NETLINK_ISCSI_SCST	25
 
-#define REGISTER_USERD		_IOW('s', 0, const char*)
+#define REGISTER_USERD		_IOW('s', 0, struct iscsi_register_info)
 #define ADD_TARGET		_IOW('s', 1, struct target_info)
 #define DEL_TARGET		_IOW('s', 2, struct target_info)
 #define ADD_SESSION		_IOW('s', 3, struct session_info)
diff --git a/iscsi-scst/kernel/config.c b/iscsi-scst/kernel/config.c
index 63a32adba..255c8d894 100644
--- a/iscsi-scst/kernel/config.c
+++ b/iscsi-scst/kernel/config.c
@@ -371,10 +371,18 @@ static int add_target(unsigned long ptr)
 
 static int iscsi_check_version(unsigned long arg)
 {
+	struct iscsi_register_info reg;
 	char ver[sizeof(ISCSI_SCST_INTERFACE_VERSION)+1];
-	int res;
+	int res, max_data_seg_len;
 
-	res = copy_from_user(ver, (void *)arg, sizeof(ver));
+	res = copy_from_user(&reg, (void *)arg, sizeof(reg));
+	if (res < 0) {
+		PRINT_ERROR("%s", "Unable to get register info");
+		goto out;
+	}
+
+	res = copy_from_user(ver, (void *)(unsigned long)reg.version,
+				sizeof(ver));
 	if (res < 0) {
 		PRINT_ERROR("%s", "Unable to get version string");
 		goto out;
@@ -382,12 +390,20 @@ static int iscsi_check_version(unsigned long arg)
 	ver[sizeof(ver)-1] = '\0';
 
 	if (strcmp(ver, ISCSI_SCST_INTERFACE_VERSION) != 0) {
-		PRINT_ERROR("Incorrect version of user space %s (needed %s)",
+		PRINT_ERROR("Incorrect version of user space %s (expected %s)",
 			ver, ISCSI_SCST_INTERFACE_VERSION);
 		res = -EINVAL;
 		goto out;
 	}
 
+	max_data_seg_len = ISCSI_CONN_IOV_MAX << PAGE_SHIFT;
+	if (reg.max_data_seg_len != max_data_seg_len) {
+		PRINT_ERROR("Incorrect max_data_seg_len %d (expected %d)",
+			reg.max_data_seg_len, max_data_seg_len);
+		res = -EINVAL;
+		goto out;
+	}
+
 out:
 	return res;
 }
diff --git a/iscsi-scst/kernel/iscsi.c b/iscsi-scst/kernel/iscsi.c
index 14c6fb600..f64a409f8 100644
--- a/iscsi-scst/kernel/iscsi.c
+++ b/iscsi-scst/kernel/iscsi.c
@@ -2907,8 +2907,6 @@ static int __init iscsi_init(void)
 		"degraded mode. Refer README file for details");
 #endif
 
-	BUILD_BUG_ON(MAX_DATA_SEG_LEN != (ISCSI_CONN_IOV_MAX<<PAGE_SHIFT));
-
 	if ((ctr_major = register_chrdev(0, ctr_name, &ctr_fops)) < 0) {
 		PRINT_ERROR("failed to register the control device %d", ctr_major);
 		err = ctr_major;
diff --git a/iscsi-scst/usr/ctldev.c b/iscsi-scst/usr/ctldev.c
index 05fdeeca1..717b58453 100644
--- a/iscsi-scst/usr/ctldev.c
+++ b/iscsi-scst/usr/ctldev.c
@@ -34,7 +34,7 @@ struct session_file_operations {
 	int (*connection_op) (int fd, u32 tid, u64 sid, u32 cid, void *arg);
 };
 
-static int ctrdev_open(void)
+static int ctrdev_open(int max_data_seg_len)
 {
 	FILE *f;
 	char devname[256];
@@ -42,6 +42,7 @@ static int ctrdev_open(void)
 	int devn;
 	int ctlfd = -1;
 	int err;
+	struct iscsi_register_info reg = { 0 };
 
 	if (!(f = fopen("/proc/devices", "r"))) {
 		perror("Cannot open control path to the driver\n");
@@ -81,9 +82,12 @@ static int ctrdev_open(void)
 		goto out;
 	}
 
-	err = ioctl(ctlfd, REGISTER_USERD, ISCSI_SCST_INTERFACE_VERSION);
+	reg.version = ISCSI_SCST_INTERFACE_VERSION;
+	reg.max_data_seg_len = max_data_seg_len;
+	err = ioctl(ctlfd, REGISTER_USERD, &reg);
 	if (err < 0) {
-		log_error("Unable to register: %s\n", strerror(errno));
+		log_error("Unable to register: %s. Incompatible version of the "
+			"kernel module?\n", strerror(errno));
 		close(ctlfd);
 		ctlfd = -1;
 		goto out;
diff --git a/iscsi-scst/usr/iscsi_scstd.c b/iscsi-scst/usr/iscsi_scstd.c
index 4edf0c4d6..f4d6bfc38 100644
--- a/iscsi-scst/usr/iscsi_scstd.c
+++ b/iscsi-scst/usr/iscsi_scstd.c
@@ -518,6 +518,42 @@ static void event_loop(int timeout)
 	}
 }
 
+int init_max_data_seg_len(void)
+{
+	int page_size = getpagesize();
+	int max_data_seg_len = page_size / sizeof(struct iovec) * page_size;
+
+	if ((session_keys[3].local_def != -1) ||
+	    (session_keys[3].max != -1) ||
+	    (session_keys[4].local_def != -1) ||
+	    (session_keys[4].max != -1) ||
+	    (session_keys[5].local_def != -1) ||
+	    (session_keys[5].max != -1) ||
+	    (session_keys[6].local_def != -1) ||
+	    (session_keys[6].max != -1)) {
+		log_error("Wrong session_keys initialization");
+		exit(-1);
+	}
+
+	/* MaxRecvDataSegmentLength */
+	session_keys[3].local_def = max_data_seg_len;
+	session_keys[3].max = max_data_seg_len;
+
+	/* MaxXmitDataSegmentLength */
+	session_keys[4].local_def = max_data_seg_len;
+	session_keys[4].max = max_data_seg_len;
+
+	/* MaxBurstLength */
+	session_keys[5].local_def = max_data_seg_len;
+	session_keys[5].max = max_data_seg_len;
+
+	/* FirstBurstLength */
+	session_keys[6].local_def = max_data_seg_len;
+	session_keys[6].max = max_data_seg_len;
+
+	return max_data_seg_len;
+}
+
 int main(int argc, char **argv)
 {
 	int ch, longindex, timeout = -1;
@@ -526,6 +562,7 @@ int main(int argc, char **argv)
 	gid_t gid = 0;
 	char *isns = NULL;
 	int isns_ac = 0;
+	int max_data_seg_len;
 
 	if (pipe(init_report_pipe) == -1) {
 		perror("pipe");
@@ -573,7 +610,9 @@ int main(int argc, char **argv)
 		exit(-1);
 	};
 
-	if ((ctrl_fd = ki->ctldev_open()) < 0)
+	max_data_seg_len = init_max_data_seg_len();
+
+	if ((ctrl_fd = ki->ctldev_open(max_data_seg_len)) < 0)
 		exit(-1);
 
 	if ((ipc_fd = iscsi_adm_request_listen()) < 0) {
diff --git a/iscsi-scst/usr/iscsid.h b/iscsi-scst/usr/iscsid.h
index 3774f0a25..aa6993b62 100644
--- a/iscsi-scst/usr/iscsid.h
+++ b/iscsi-scst/usr/iscsid.h
@@ -210,7 +210,7 @@ extern int iscsi_adm_request_handle(int accept_fd);
 
 /* ctldev.c */
 struct iscsi_kernel_interface {
-	int (*ctldev_open) (void);
+	int (*ctldev_open) (int);
 	int (*param_get) (u32, u64, int, struct iscsi_param *, int);
 	int (*param_set) (u32, u64, int, u32, struct iscsi_param *, int);
 	int (*target_create) (u32 *, char *);
diff --git a/iscsi-scst/usr/param.c b/iscsi-scst/usr/param.c
index 3fe20e5f0..c53ee6925 100644
--- a/iscsi-scst/usr/param.c
+++ b/iscsi-scst/usr/param.c
@@ -293,10 +293,10 @@ struct iscsi_key session_keys[] = {
 	{"InitialR2T", 1, 0, 0, 1, &or_ops},
 	{"ImmediateData", 1, 1, 0, 1, &and_ops},
 	{"MaxConnections", 1, 1, 1, 1, &minimum_ops},
-	{"MaxRecvDataSegmentLength", 8192, MAX_DATA_SEG_LEN, 512, MAX_DATA_SEG_LEN, &minimum_ops},
-	{"MaxXmitDataSegmentLength", 8192, MAX_DATA_SEG_LEN, 512, MAX_DATA_SEG_LEN, &minimum_ops},
-	{"MaxBurstLength", 262144, MAX_DATA_SEG_LEN, 512, MAX_DATA_SEG_LEN, &minimum_ops},
-	{"FirstBurstLength", 65536, MAX_DATA_SEG_LEN, 512, MAX_DATA_SEG_LEN, &minimum_ops},
+	{"MaxRecvDataSegmentLength", 8192, -1, 512, -1, &minimum_ops},
+	{"MaxXmitDataSegmentLength", 8192, -1, 512, -1, &minimum_ops},
+	{"MaxBurstLength", 262144, -1, 512, -1, &minimum_ops},
+	{"FirstBurstLength", 65536, -1, 512, -1, &minimum_ops},
 	{"DefaultTime2Wait", 2, 2, 0, 3600, &maximum_ops},
 	{"DefaultTime2Retain", 20, 20, 0, 3600, &minimum_ops},
 	{"MaxOutstandingR2T", 1, 20, 1, 65535, &minimum_ops},