hkhan,
You will need to implement a cron job that will clean up your archive directory archive log files. Before doing this, you need to consider your entire backup strategy (do you do cold or hot backups, what is backed up onto tape and when, how much roll-forward is acceptable in case you need to restore from backups, etc.). Please note that I'm on an HP-UX platform, and things may be a bit different on Sun Solaris.
The following is some sample code to clean up archive log files:
.
# List archive logs about to be deleted
find /u09/oracledata/archivelogs -name 'arch*.log' -atime +6 -exec ll {} \;
# Delete archive logs
find /u09/oracledata/archivelogs -name 'arch*.log' -atime +6 -exec rm -f {} \;
.
This code first lists the files about to be deleted, and then deletes them. It assumes that your archive log files are in the /u09/oracledata/archivelogs directory, and that they are the only files named arch*.log in that directory. The +6 selects files that were last accessed over 6 days ago. Of course, you will want to use your own site-specific information for directories, names, and retention days.
Hope this helps.
Don Sauve
Wagstaff, Inc.
OW XE, SP15.1, HP-UX 11.0, Oracle 8.1.6