cbbackup does not backup all buckets when there is not option -b in command

Install couchbase server EE 3.0.0-520
Create 2 buckets, default and sasl-2
Load 10K items to each bucket
Do full backup
Only one backup was backup

[root@centos-64-x64 ~]# /opt/couchbase/bin/cbbackup http://127.0.0.1:8091 /backup/backup-1
################### 100.0% (10000/estimated 10000 msgs)
bucket: default, msgs transferred...
: total | last | per sec
byte : 100000 | 100000 | 39891.1
done

Backup folder has only one default bucket
[root@centos-64-x64 ~]# ls /backup/backup-1/2014-03-27T232545Z/2014-03-27T232545Z-full/
bucket-default

[root@centos-64-x64 ~]# ls -lh /opt/couchbase/var/lib/couchbase/data/
total 84K
drwxrwx---. 2 couchbase couchbase 36K Mar 27 16:52 default
rw-rw---. 1 couchbase couchbase 34 Mar 27 16:13 _replicator.couch.1
drwxrwx---. 2 couchbase couchbase 36K Mar 27 16:52 sasl-2
rw-rw---. 1 couchbase couchbase 4.1K Mar 27 16:12 _users.couch.1