ns-120 config backup.

guys,

i am trying to backup ns-120 config. i am using the below command and it always throws error.

/nas/sbin/nasdb_backup /nas/home/nasadmin Nov18-2010

CRITICAL FAULT:
        NAS_DB path given must be a directory

I have set it NAS_DB=/nas

$ env |grep nas

MANPATH=/usr/share/man:/usr/man:/nas/man
USER=nasadmin
MAIL=/var/spool/mail/nasadmin
PATH=/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/home/nasadmin/bin:/nas/bin
PWD=/home/nasadmin
HOME=/home/nasadmin
NAS_DB=/nas
LOGNAME=nasadmin

any suggestions are highly appreciated.

thank you,

kayan.