Script to monitor the ASM disk usage in Oracle

The following disk gives you an idea of the Total size, used size, and percentage of space used.

SET LINESIZE 150 
SET PAGESIZE 9999 
SET VERIFY off
COLUMN group_name 
FORMAT a25 HEAD 'DISKGROUP_NAME' 
COLUMN state FORMAT a11 HEAD 'STATE' 
COLUMN type FORMAT a6 HEAD 'TYPE' 
COLUMN total_mb FORMAT 999,999,999 HEAD 'TOTAL SIZE(GB)' 
COLUMN free_mb FORMAT 999,999,999 HEAD 'FREE SIZE (GB)' 
COLUMN used_mb FORMAT 999,999,999 HEAD 'USED SIZE (GB)' 
COLUMN pct_used FORMAT 999.99 HEAD 'PERCENTAGE USED' 
SELECT distinct name group_name , state state , type type , 
round(total_mb/1024) TOTAL_GB , round(free_mb/1024) free_gb , 
round((total_mb - free_mb) / 1024) used_gb , 
round((1- (free_mb / total_mb))*100, 2) pct_used from 
v$asm_diskgroup where round((1- (free_mb / total_mb))*100, 2) > 90 ORDER BY 
name;

You can schedule this script in Crontab to give you an alert daily as an automation

Save the following file in shell format

cat asmscriptusage.sh

export ORACLE_HOME=/u01/app/oracle/product/12.2.0/dbhome_1
export ORACLE_SID=PRIMDB
export PATH=$ORACLE_HOME/bin:$PATH
logfile=/u03/log/asm_dg.log
sqlplus -s "/as sysdba" > /dev/null << EOF spool $logfile 
SET LINESIZE 150 
SET PAGESIZE 9999 
SET VERIFY off
COLUMN group_name 
FORMAT a25 HEAD 'DISKGROUP_NAME' 
COLUMN state FORMAT a11 HEAD 'STATE' 
COLUMN type FORMAT a6 HEAD 'TYPE' 
COLUMN total_mb FORMAT 999,999,999 HEAD 'TOTAL SIZE(GB)' 
COLUMN free_mb FORMAT 999,999,999 HEAD 'FREE SIZE (GB)' 
COLUMN used_mb FORMAT 999,999,999 HEAD 'USED SIZE (GB)' 
COLUMN pct_used FORMAT 999.99 HEAD 'PERCENTAGE USED' 
SELECT distinct name group_name , state state , type type , 
round(total_mb/1024) TOTAL_GB , round(free_mb/1024) free_gb , 
round((total_mb - free_mb) / 1024) used_gb , 
round((1- (free_mb / total_mb))*100, 2) pct_used from 
v$asm_diskgroup where round((1- (free_mb / total_mb))*100, 2) > 90 ORDER BY 
name;
spool off
exit
EOF
count=`cat $logfile|wc -l`
#echo $count
if [ $count -ge 4 ];
then
 mailx -s "ASM DISKGROUP REACHED 90% UTILIZATION" dbasupport@gmail.com < 
$logfile
fi

Note: The script will trigger a mail alert if the utilization of the ASM disk group reaches 90 percent