diff --git a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache.c b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache.c
index a4e59e1..d28f96f 100644
--- a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache.c
+++ b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache.c
@@ -268,11 +268,11 @@ int cache_set_int(char *key, const NotifierID value)
 	if (rv < 0 || rv >= PATH_MAX)
 		return rv;
 	if ((fp = fopen(tmpfile, "w")) == NULL)
-		return 1;
+		abort_io("open", tmpfile);
 	fprintf(fp, "%ld", value);
 	rv = fclose(fp);
 	if (rv != 0)
-		return rv;
+		abort_io("close", tmpfile);
 
 	rv = snprintf(file, PATH_MAX, "%s/%s", cache_dir, key);
 	if (rv < 0 || rv >= PATH_MAX)
@@ -700,7 +700,7 @@ int cache_free_cursor(DBC *cur)
 
 int cache_close(void)
 {
-	int rv;
+	int rv = 0;
 
 	if (dbp && (rv = dbp->close(dbp, 0)) != 0) {
 		dbp->err(dbp, rv, "close");
diff --git a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.c b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.c
index f6797e4..38b2d6c 100644
--- a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.c
+++ b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.c
@@ -37,6 +37,7 @@
 #include <ctype.h>
 #include <stdbool.h>
 #include <limits.h>
+#include <errno.h>
 #include <sys/types.h>
 
 #include <univention/debug.h>
@@ -279,10 +280,12 @@ int parse_entry(void *data, u_int32_t size, CacheEntry *entry)
 			rv = snprintf(filename, PATH_MAX, "%s/bad_cache", cache_dir);
 			if (rv < 0 || rv >= PATH_MAX)
 				abort();
-			if ((file = fopen(filename, "w")) != NULL) {
-				fprintf(file, "Check log file");
-				fclose(file);
-			}
+			if ((file = fopen(filename, "w")) == NULL)
+				abort_io("open", filename);
+			fprintf(file, "Check log file");
+			rv = fclose(file);
+			if (rv != 0)
+				abort_io("close", filename);
 
 			return -1;
 		}
@@ -290,3 +293,9 @@ int parse_entry(void *data, u_int32_t size, CacheEntry *entry)
 
 	return 0;
 }
+
+void abort_io(const char *func, const char *filename)
+{
+	univention_debug(UV_DEBUG_LISTENER, UV_DEBUG_ERROR, "Fatal %s(%s): %s", func, filename, strerror(errno));
+	abort();
+}
diff --git a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.h b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.h
index e19d6d4..55e2ae9 100644
--- a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.h
+++ b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/cache_lowlevel.h
@@ -42,5 +42,6 @@ int	parse_entry	(void		 *data,
 			 u_int32_t	  size,
 			 CacheEntry	 *entry);
 void hex_dump(int level, void *data, u_int32_t start, u_int32_t size);
+void abort_io(const char *func, const char *filename) __attribute__((noreturn));
 
 #endif /* _CACHE_LOWLEVEL_ */
diff --git a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/handlers.c b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/handlers.c
index 7d89581..06c2ab1 100644
--- a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/handlers.c
+++ b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/handlers.c
@@ -550,7 +550,9 @@ void handler_write_state(Handler *handler) {
 		univention_debug(UV_DEBUG_LISTENER, UV_DEBUG_ERROR, "could not open %s", state_filename);
 	} else {
 		fprintf(state_fp, "%d", handler->state);
-		fclose(state_fp);
+		rv = fclose(state_fp);
+		if (rv != 0)
+			abort_io("close", state_filename);
 	}
 }
 
diff --git a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/transfile.c b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/transfile.c
index 15459ec..3abb31e 100644
--- a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/transfile.c
+++ b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/transfile.c
@@ -92,8 +92,10 @@ static FILE* fopen_lock(const char *name, const char *type, FILE **l_file)
 /* Close file and lock file. */
 static int fclose_lock(FILE **file, FILE **l_file)
 {
+	int rv = 0;
+
 	if (*file != NULL) {
-		fclose(*file);
+		rv |= fclose(*file);
 		*file = NULL;
 	}
 
@@ -102,11 +104,11 @@ static int fclose_lock(FILE **file, FILE **l_file)
 		int rc = lockf(l_fd, F_ULOCK, 0);
 		if (rc)
 			univention_debug(UV_DEBUG_LDAP, UV_DEBUG_ALL, "unlockf(): %d", rc);
-		fclose(*l_file);
+		rv |= fclose(*l_file);
 		*l_file = NULL;
 	}
 
-	return 0;
+	return rv;
 }
 
 
diff --git a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/notifier.c b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/notifier.c
index 5c806cb..cf49f31 100644
--- a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/notifier.c
+++ b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/src/notifier.c
@@ -43,8 +43,10 @@
 #include <string.h>
 #include <time.h>
 #include <sys/time.h>
+#include <sys/statvfs.h>
 
 #include <univention/debug.h>
+#include <univention/config.h>
 #include <univention/ldap.h>
 #ifdef WITH_KRB5
 #include <univention/krb5.h>
@@ -84,6 +86,37 @@ static int connect_to_ldap(univention_ldap_parameters_t *lp,
 	return LDAP_SUCCESS;
 }
 
+static void check_free_space()
+{
+	static int min_mib = -2;
+	const char *dirnames[] = {
+		cache_dir,
+		ldap_dir,
+		NULL
+	}, **dirname;
+
+	if (min_mib == -2)
+		min_mib = univention_config_get_int("listener/freespace");
+
+	if (min_mib <= 0)
+		return;
+
+	for (dirname=dirnames; *dirname; dirname++) {
+		struct statvfs buf;
+		int free_mib;
+
+		if (statvfs(*dirname, &buf))
+			continue;
+
+		free_mib = ((long)buf.f_bavail * (long)buf.f_frsize) >> 20;
+		if (free_mib >= min_mib)
+			continue;
+
+		univention_debug(UV_DEBUG_LISTENER, UV_DEBUG_ERROR, "File system '%s' full: %d < %d", *dirname, free_mib, min_mib);
+		abort();
+	}
+}
+
 /* listen for ldap updates */
 int notifier_listen(univention_ldap_parameters_t *lp,
 		univention_krb5_parameters_t *kp,
@@ -101,6 +134,8 @@ int notifier_listen(univention_ldap_parameters_t *lp,
 		int		msgid;
 		time_t		timeout = DELAY_LDAP_CLOSE;
 
+		check_free_space();
+
 		univention_debug(UV_DEBUG_LISTENER, UV_DEBUG_INFO, "Last Notifier ID: %lu", id);
 		if ((msgid = notifier_get_dn(NULL, id + 1)) < 1)
 			break;
diff --git a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/debian/univention-directory-listener.univention-config-registry-variables b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/debian/univention-directory-listener.univention-config-registry-variables
index d0362d3..574a161 100644
--- a/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/debian/univention-directory-listener.univention-config-registry-variables
+++ b/branches/ucs-4.1/ucs-4.1-3/management/univention-directory-listener/debian/univention-directory-listener.univention-config-registry-variables
@@ -45,3 +45,9 @@ Description[de]=Anzahl der Versuche zum Verbindungsaufbau zum LDAP-Server im Fal
 Description[en]=Number of retries to re-connect the LDAP server in case of errors. Default: 5
 Type=int
 Categories=service-ln
+
+[listener/freespace]
+Description[de]=Diese Variable legt die untere Grenze für den freien Speicherplatz in den Verzeichnissen '/var/lib/univention-ldap/' und '/var/lib/univention-directory-listener/', ab der der Listener gestoppt wird. Standard is 10 [MiB].
+Description[en]=This variable configures the lower limit for free space in the directories '/var/lib/univention-ldap/' and '/var/lib/univention-directory-listener/', when the Listener will be stopped. Default is 10 [MiB].
+Type=int
+Categories=service-ln