diff --git a/Makefile b/Makefile
index 6bdaed9..7c656e3 100644
--- a/Makefile
+++ b/Makefile
@@ -107,7 +107,7 @@ OBJS =  mdadm.o config.o policy.o mdstat.o  ReadMe.o util.o maps.o lib.o \
 	restripe.o sysfs.o sha1.o mapfile.o crc32.o sg_io.o msg.o \
 	platform-intel.o probe_roms.o
 
-OBJSX = restripe.o
+CHECK_OBJS = restripe.o sysfs.o maps.o lib.o
 
 SRCS =  $(patsubst %.o,%.c,$(OBJS))
 
@@ -177,8 +177,8 @@ msg.o: msg.c msg.h
 test_stripe : restripe.c mdadm.h
 	$(CC) $(CXFLAGS) $(LDFLAGS) -o test_stripe -DMAIN restripe.c
 
-raid6check : raid6check.o mdadm.h $(OBJSX)
-	$(CC) $(CXFLAGS) $(LDFLAGS) -o raid6check raid6check.o $(OBJSX)
+raid6check : raid6check.o mdadm.h $(CHECK_OBJS)
+	$(CC) $(CXFLAGS) $(LDFLAGS) -o raid6check raid6check.o $(CHECK_OBJS)
 
 mdassemble : $(ASSEMBLE_SRCS) $(INCL)
 	rm -f $(OBJS)
diff --git a/raid6check.c b/raid6check.c
index 97e3f1c..9d450da 100644
--- a/raid6check.c
+++ b/raid6check.c
@@ -159,7 +159,7 @@ int check_stripes(int *source, unsigned long long *offsets,
 				       level, layout);
 		}
 		if(disk >= 0) {
-			printf("Possible failed disk: %d --> %s\n", disk, name[disk]);
+			printf("Possible failed disk slot: %d --> %s\n", disk, name[disk]);
 		}
 		if(disk == -65535) {
 			printf("Failure detected, but disk unknown\n");
@@ -192,71 +192,121 @@ unsigned long long getnum(char *str, char **err)
 
 int main(int argc, char *argv[])
 {
-	/* raid_disks chunk_size layout start length devices...
-	 */
+	/* md_device start length */
 	int *fds;
 	char *buf;
+	char **disk_name;
 	unsigned long long *offsets;
 	int raid_disks, chunk_size, layout;
 	int level = 6;
 	unsigned long long start, length;
 	int i;
-
+	int mdfd;
+	struct mdinfo *info, *comp;
 	char *err = NULL;
-	if (argc < 8) {
-		fprintf(stderr, "Usage: raid6check raid_disks"
-			" chunk_size layout start length devices...\n");
+	const char prg[] = "raid6check";
+
+	if (argc < 3) {
+		fprintf(stderr, "Usage: %s md_device start length\n", prg);
 		exit(1);
 	}
 
-	raid_disks = getnum(argv[1], &err);
-	chunk_size = getnum(argv[2], &err);
-	layout = getnum(argv[3], &err);
-	start = getnum(argv[4], &err);
-	length = getnum(argv[5], &err);
+	mdfd = open(argv[1], O_RDONLY);
+	if(mdfd < 0) {
+		perror(argv[1]);
+		fprintf(stderr,"%s: cannot open %s\n", prg, argv[1]);
+		exit(4);
+	}
+
+	info = sysfs_read(mdfd, -1,
+			  GET_LEVEL|
+			  GET_LAYOUT|
+			  GET_DISKS|
+			  GET_COMPONENT|
+			  GET_CHUNK|
+			  GET_DEVS|
+			  GET_OFFSET|
+			  GET_SIZE);
+
+	if(info->array.level != level) {
+		fprintf(stderr, "%s: %s not a RAID-6\n", prg, argv[1]);
+		exit(5);
+	}
+
+	printf("layout: %d\n", info->array.layout);
+	printf("disks: %d\n", info->array.raid_disks);
+	printf("component size: %llu\n", info->component_size*512);
+	printf("chunk size: %d\n", info->array.chunk_size);
+	printf("\n");
+
+	comp = info->devs;
+	for(i = 0; i < info->array.raid_disks; i++) {
+		printf("disk: %d - offset: %llu - size: %llu - name: %s - slot: %d\n",
+			i, comp->data_offset, comp->component_size*512,
+			map_dev(comp->disk.major, comp->disk.minor, 0),
+			comp->disk.raid_disk);
+
+		comp = comp->next;
+	}
+	printf("\n");
+
+	close(mdfd);
+
+	raid_disks = info->array.raid_disks;
+	chunk_size = info->array.chunk_size;
+	layout = info->array.layout;
+	start = getnum(argv[2], &err);
+	length = getnum(argv[3], &err);
+
 	if (err) {
-		fprintf(stderr, "test_stripe: Bad number: %s\n", err);
+		fprintf(stderr, "%s: Bad number: %s\n", prg, err);
 		exit(2);
 	}
-	if (argc != raid_disks + 6) {
-		fprintf(stderr, "test_stripe: wrong number of devices: want %d found %d\n",
-			raid_disks, argc-6);
-		exit(2);
+
+	start = (start / chunk_size) * chunk_size;
+
+	if(length == 0) {
+		length = info->component_size * 512 - start;
 	}
+
+	disk_name = malloc(raid_disks * sizeof(*disk_name));
 	fds = malloc(raid_disks * sizeof(*fds));
 	offsets = malloc(raid_disks * sizeof(*offsets));
 	memset(offsets, 0, raid_disks * sizeof(*offsets));
 
+	comp = info->devs;
 	for (i=0; i<raid_disks; i++) {
-		char *p;
-		p = strchr(argv[6+i], ':');
-
-		if(p != NULL) {
-			*p++ = '\0';
-			offsets[i] = atoll(p) * 512;
-		}
-		fds[i] = open(argv[6+i], O_RDWR);
-		if (fds[i] < 0) {
-			perror(argv[6+i]);
-			fprintf(stderr,"test_stripe: cannot open %s.\n", argv[6+i]);
+		int disk_slot = comp->disk.raid_disk;
+		disk_name[disk_slot] = map_dev(comp->disk.major, comp->disk.minor, 0);
+		offsets[disk_slot] = comp->data_offset * 512;
+		fds[disk_slot] = open(disk_name[disk_slot], O_RDWR);
+		if (fds[disk_slot] < 0) {
+			perror(disk_name[disk_slot]);
+			fprintf(stderr,"%s: cannot open %s\n", prg, disk_name[disk_slot]);
 			exit(3);
 		}
+
+		comp = comp->next;
 	}
 
 	buf = malloc(raid_disks * chunk_size);
 
 	int rv = check_stripes(fds, offsets,
 			       raid_disks, chunk_size, level, layout,
-			       start, length, &argv[6]);
+			       start, length, disk_name);
 	if (rv != 0) {
 		fprintf(stderr,
-			"test_stripe: test_stripes returned %d\n", rv);
+			"%s: check_stripes returned %d\n", prg, rv);
 		exit(1);
 	}
 
+	free(disk_name);
 	free(fds);
 	free(offsets);
 	free(buf);
 
+	for(i=0; i<raid_disks; i++)
+		close(fds[i]);
+
 	exit(0);
 }