This is regarding monitoring of Oracle RAC DB, we had scenario where all the space had been filled up of DB and still no alert generated from ASM_DATA_DISK which would say that free space is low.
Although there was another below mentioned connection error alert generated :
Profile DB name(**-**-**) - Custom Checkpoints (Instance name : ORA-00257: archiver error. Connect internal only, until freed.
which says that "You have run out of logical or physical space on the mount, disk "
Can someone please to identify that why it happened and how can we fix it so that there wont be any miss in future because these are very critical alerts.