diff --git a/Dockerfile b/Dockerfile
index a07ec3c..a8f40fc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM mongo:3.0
+FROM mongo:3.0.11
 MAINTAINER Ilya Stepanov <dev@ilyastepanov.com>
 
 RUN apt-get update && \
diff --git a/README.md b/README.md
index 262c235..6f594b2 100644
--- a/README.md
+++ b/README.md
@@ -19,3 +19,15 @@ To run backup once without cron job, add `no-cron` parameter:
         -v /path/to/target/folder:/backup \ # where to put backups
         --link my-mongo-container:mongo \   # linked container with running mongo
         istepanov/mongodump no-cron
+
+To backup only one database, set environment variable `MONGO_DB_NAME`
+
+    docker run -d \
+        -v /path/to/target/folder:/backup \ # where to put backups
+        -e 'CRON_SCHEDULE=0 1 * * *' \      # cron job schedule
+        -e 'MONGO_DB_NAME=<db_name>' \     # set database name
+        --link my-mongo-container:mongo \   # linked container with running mongo
+        istepanov/mongodump
+
+By default, backups available for last 30 days only. To manage it, set environment
+variable `MONGO_BACKUP_EXPIRE_DAYS`
diff --git a/backup.sh b/backup.sh
index f24f578..659509c 100644
--- a/backup.sh
+++ b/backup.sh
@@ -7,8 +7,30 @@ echo "Job started: $(date)"
 DATE=$(date +%Y%m%d_%H%M%S)
 FILE="/backup/backup-$DATE.tar.gz"
 
-mongodump --quiet -h $MONGO_PORT_27017_TCP_ADDR -p $MONGO_PORT_27017_TCP_PORT
+arr=("--quiet" "-h" "$MONGO_PORT_27017_TCP_ADDR" "-p" "$MONGO_PORT_27017_TCP_PORT")
+if [ ! -z $MONGO_DB_NAME ]; then
+	arr+=("-d")
+	arr+=("$MONGO_DB_NAME")
+fi
+mongodump "${arr[@]}"
 tar -zcvf $FILE dump/
 rm -rf dump/
-
 echo "Job finished: $(date)"
+echo "Start autoclean"
+FILES=/backup/*.tar.gz
+currtime=`date +%s`
+for f in $FILES
+do
+	if [ -f $f ];
+	then
+		filemtime=`stat -c %Y $f`
+		diff=$(( (currtime - filemtime)/86400))
+		if (($diff > $MONGO_BACKUP_EXPIRE_DAYS));
+		then
+			echo "deleting '$f' ..."
+			rm $f
+			echo "deleted."
+		fi
+	fi
+done
+echo "End autoclean"
diff --git a/start.sh b/start.sh
index 34cf936..3b98aec 100644
--- a/start.sh
+++ b/start.sh
@@ -3,7 +3,7 @@
 set -e
 
 CRON_SCHEDULE=${CRON_SCHEDULE:-0 1 * * *}
-
+MONGO_BACKUP_EXPIRE_DAYS=${MONGO_BACKUP_EXPIRE_DAYS:-30}
 if [[ "$1" == 'no-cron' ]]; then
     exec /backup.sh
 else
@@ -13,6 +13,9 @@ else
     fi
     CRON_ENV="MONGO_PORT_27017_TCP_ADDR='$MONGO_PORT_27017_TCP_ADDR'"
     CRON_ENV="$CRON_ENV\nMONGO_PORT_27017_TCP_PORT='$MONGO_PORT_27017_TCP_PORT'"
+    CRON_ENV="$CRON_ENV\nMONGO_DB_NAME='$MONGO_DB_NAME'"
+    CRON_ENV="$CRON_ENV\nMONGO_BACKUP_EXPIRE_DAYS=$MONGO_BACKUP_EXPIRE_DAYS"
+    CRON_ENV="$CRON_ENV\nTZ=$TZ"
     echo -e "$CRON_ENV\n$CRON_SCHEDULE /backup.sh > $LOGFIFO 2>&1" | crontab -
     crontab -l
     cron