diff --git a/daemon/Makefile.am b/daemon/Makefile.am
index 7757067..c4a30bc 100644
--- a/daemon/Makefile.am
+++ b/daemon/Makefile.am
@@ -129,6 +129,7 @@ guestfsd_SOURCES = \
 	luks.c \
 	lvm.c \
 	lvm-filter.c \
+	md.c \
 	mkfs.c \
 	mknod.c \
 	modprobe.c \
diff --git a/daemon/daemon.h b/daemon/daemon.h
index 6ed68fd..3ca4693 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -47,6 +47,7 @@ extern int xwrite (int sock, const void *buf, size_t len)
 extern int xread (int sock, void *buf, size_t len)
   __attribute__((__warn_unused_result__));
 
+extern int add_string_nodup (char ***argv, int *size, int *alloc, char *str);
 extern int add_string (char ***argv, int *size, int *alloc, const char *str);
 extern size_t count_strings (char *const *argv);
 extern void sort_strings (char **argv, int len);
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index eacbc1d..930ee27 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -415,10 +415,9 @@ xread (int sock, void *v_buf, size_t len)
 }
 
 int
-add_string (char ***argv, int *size, int *alloc, const char *str)
+add_string_nodup (char ***argv, int *size, int *alloc, char *str)
 {
   char **new_argv;
-  char *new_str;
 
   if (*size >= *alloc) {
     *alloc += 64;
@@ -426,11 +425,23 @@ add_string (char ***argv, int *size, int *alloc, const char *str)
     if (new_argv == NULL) {
       reply_with_perror ("realloc");
       free_strings (*argv);
+      *argv = NULL;
       return -1;
     }
     *argv = new_argv;
   }
 
+  (*argv)[*size] = str;
+
+  (*size)++;
+  return 0;
+}
+
+int
+add_string (char ***argv, int *size, int *alloc, const char *str)
+{
+  char *new_str;
+
   if (str) {
     new_str = strdup (str);
     if (new_str == NULL) {
@@ -438,13 +449,11 @@ add_string (char ***argv, int *size, int *alloc, const char *str)
       free_strings (*argv);
       return -1;
     }
-  } else
+  } else {
     new_str = NULL;
+  }
 
-  (*argv)[*size] = new_str;
-
-  (*size)++;
-  return 0;
+  return add_string_nodup (argv, size, alloc, new_str);
 }
 
 size_t
diff --git a/daemon/md.c b/daemon/md.c
new file mode 100644
index 0000000..95bd7fa
--- /dev/null
+++ b/daemon/md.c
@@ -0,0 +1,88 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2011 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <config.h>
+
+#include <glob.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "daemon.h"
+#include "actions.h"
+
+static int
+glob_errfunc (const char *epath, int eerrno)
+{
+    fprintf(stderr, "glob: failure reading %s: %s\n", epath, strerror(eerrno));
+
+    return 1;
+}
+
+char **
+do_list_md_devices (void)
+{
+    char **r = NULL;
+    int size = 0, alloc = 0;
+    glob_t mds;
+
+    memset(&mds, 0, sizeof(mds));
+
+#define PREFIX "/sys/block/md"
+#define SUFFIX "/md"
+
+    /* Look for directories under /sys/block matching md[0-9]*
+     * As an additional check, we also make sure they have a md subdirectory */
+    int err = glob(PREFIX "[0-9]*" SUFFIX, GLOB_ERR, glob_errfunc, &mds);
+    if (err == GLOB_NOSPACE) {
+        reply_with_error("glob: returned GLOB_NOSPACE: "
+                         "rerun with LIBGUESTFS_DEBUG=1");
+        goto error;
+    } else if (err == GLOB_ABORTED) {
+        reply_with_error("glob: returned GLOB_ABORTED: "
+                         "rerun with LIBGUESTFS_DEBUG=1");
+        goto error;
+    }
+
+    for (size_t i = 0; i < mds.gl_pathc; i++) {
+        size_t len = strlen(mds.gl_pathv[i]) - strlen(PREFIX) - strlen(SUFFIX);
+
+#define DEV "/dev/md"
+        char *dev = malloc(strlen(DEV) + len  + 1);
+        if (NULL == dev) {
+            reply_with_perror("malloc");
+            goto error;
+        }
+
+        char *n = dev;
+        n = mempcpy(n, DEV, strlen(DEV));
+        n = mempcpy(n, &mds.gl_pathv[i][strlen(PREFIX)], len);
+        *n = '\0';
+
+        if (add_string_nodup(&r, &size, &alloc, dev) == -1) goto error;
+    }
+
+    if (add_string_nodup(&r, &size, &alloc, NULL) == -1) goto error;
+    globfree(&mds);
+
+    return r;
+
+error:
+    globfree(&mds);
+    if (r != NULL) free_strings(r);
+    return NULL;
+}
diff --git a/generator/generator_actions.ml b/generator/generator_actions.ml
index d3fa3e0..a836ab5 100644
--- a/generator/generator_actions.ml
+++ b/generator/generator_actions.ml
@@ -6332,6 +6332,16 @@ is for copying blocks within existing files.  See C<guestfs_cp>,
 C<guestfs_cp_a> and C<guestfs_mv> for general file copying and
 moving functions.");
 
+  ("list_md_devices", (RStringList "devices", [], []), 298, [],
+   [],
+   "list Linux MD devices",
+   "\
+List all Linux MD devices.
+
+The non-textual names as known to the appliance are returned, eg.
+C</dev/md127>. Note that this will normally be different to the name used by the
+guest.");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 0ed9e45..fcc612d 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -48,6 +48,7 @@ daemon/ls.c
 daemon/luks.c
 daemon/lvm-filter.c
 daemon/lvm.c
+daemon/md.c
 daemon/mkfs.c
 daemon/mknod.c
 daemon/modprobe.c
diff --git a/regressions/Makefile.am b/regressions/Makefile.am
index 0af7e8c..d47e3fa 100644
--- a/regressions/Makefile.am
+++ b/regressions/Makefile.am
@@ -45,6 +45,7 @@ TESTS = \
 	test-guestfish-tilde.sh \
 	test-inspect-fstab.sh \
 	test-launch-race.pl \
+	test-list-md-devices.sh \
 	test-luks.sh \
 	test-luks-list.sh \
 	test-lvm-filtering.sh \
diff --git a/regressions/test-list-md-devices.sh b/regressions/test-list-md-devices.sh
new file mode 100755
index 0000000..50ae089
--- /dev/null
+++ b/regressions/test-list-md-devices.sh
@@ -0,0 +1,59 @@
+#!/bin/bash -
+# libguestfs
+# Copyright (C) 2011 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+# Test guestfish list-md-devices command
+
+set -e
+
+output=$(
+../fish/guestfish <<EOF
+# Add 2 empty disks
+sparse md-test1.img 100M
+sparse md-test2.img 100M
+run
+
+# list-md-devices should return nothing
+list-md-devices
+
+# Create a raid1 based on the 2 disks
+debug sh "/usr/bin/yes | mdadm -C /dev/md/test --level=1 --raid-devices=2 /dev/vda /dev/vdb >/dev/null 2>&1"
+EOF
+)
+
+# Ensure list-md-devices above returned nothing
+if [ ! -z "$output" ]; then
+    echo "$0: error: output of list-md-devices with no MD devices did not match expected output"
+    echo $output
+    exit 1;
+fi
+
+# Ensure list-md-devices now returns the newly created md device
+output=$(
+../fish/guestfish -a md-test1.img -a md-test2.img <<EOF
+run
+list-md-devices
+EOF
+)
+
+if [ "$output" != "/dev/md127" ]; then
+    echo "$0: error: output of list-md-devices did not match expected output"
+    echo "$output"
+    exit 1
+fi
+
+rm -f md-test1.img md-test2.img
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 95de1ee..a1f7f63 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-297
+298
