How to set Spark storage level to DISK_ONLY

[jayprajapati857]

i want to persist the data into the spark application and set the storageLevel to DISK_ONLY. currently i am setting the storage level to spark-defaults.conf like

spark.storage.StorageLevel DISK_ONLY

while running spark application this storage level is set to DISK_ONLY in environment tab on spark ui but when the data persistance is complete the spark ui shows that memory used is something MBs and Disk Used 0.

in spark-shell i am able to set this storage level but i dont know how to set it using Mobius.

so how can i set that storageLevel?