How to release the lock of database?

Hi, All, I have problems to access the database.... I think this problem happens because i tried to install DBD-Informix which accessed the demo database but it does not exist on my server. Before that action, it works well. So I think my environment variable is all set.(including INFORMIXDIR , INFORMIXSERVER, DBPATH....) And after that the problem happens!!! I tried to use " ps -aux" to see which process is run away and kill it, but it didn't work. Then i reinstalled the Redhat Linux 6.0, Informix SE , ISQL, ESQL/C,etc. and when i use "isql"(the same as dbaccess) to create(or select) database, it answers me the error message: 908: try to connect to the database server (dbs_rm) failed. ISAM Error: the record has been locked. p.s. "dbs_rm" is my INFORMIXSERVER name. my /home/informix/etc/sqlhosts : dbs_rm sesoctcp dbserver dbs_services I add " dbs_services 8888/tcp" to my /etc/services I don't know how to release the lock.... Thank you for your help .....