The CAD or PTMS database usually is structured by Oracle RAC with shared storage.
The Oracle ASM disk is created on the shared storage, and all the archive log backup and oracle tablespace data files locate on it.
To check the disk space usage rate, we need to log onto the ASM disk:
# su - grid
> asmcmd
ASMCMD> lsdg
State Type Rebal Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files Name
MOUNTED EXTERN N 512 4096 1048576 204800 204427 0 204427 0 N DG_BACKUP/
MOUNTED EXTERN N 512 4096 1048576 307200 295154 0 295154 0 N DG_DATA/
MOUNTED EXTERN N 512 4096 1048576 102400 102305 0 102305 0 N DG_INDEX/
MOUNTED EXTERN N 512 4096 1048576 20480 20084 0 20084 0 Y DG_OCR/
MOUNTED EXTERN N 512 4096 1048576 122880 71388 0 71388 0 N DG_ORA/
ASMCMD>
ASMCMD>
ASMCMD> cd dg_backup
ASMCMD> cd IPCC/ARCHIVELOG
ASMCMD> ls
2019_06_12/
ASMCMD> du
Used_MB Mirror_used_MB
269 269
ASMCMD>