I think you should set log_archive_dest_1 parameter. I assume that your database in ARCHIVELOG mode, but it couldn't find to archive the archived redo logs, that's why by default it archives it to /dbs folder.
You should give log_archive_dest_1 parameter a correct value, and restart database
Edit your initorcl.ora file, give log_archive_dest_1='/anydirectory'
Create spfile from pfile. restart your database, run
ALTER SYSTEM SWITCH LOGFILE;
and check, whether it created new archived redo log file in /dbs directory, or to the directory which was assigned to the parameter log_archive_dest_1
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.
Here's the latest findings. I'm sure no one has moved those files into the /dbs directory.
RMAN> change archivelog until time 'sysdate-1' delete;
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=130 device type=DISK
List of Archived Log Copies for database with db_unique_name ORCL
Key Thrd Seq S Low Time
------- ---- ------- - ---------
96 1 38 A 26-APR-09
Do you really want to delete the above objects (enter YES or NO)? yes
deleted archived log
archived log file name=/u01/app/oracle/product/11.1.0/db_1/dbs/arch1_38_682014240.dbf RECID=96 STAMP=685550413
Deleted 1 objects