[INS-30515] OCR disks size and count by redundancy
In oracle RAC,OCR file is accessed by clusterware to start the crsd agents and processes.
Have you wondered,how much size and how many disks should we allocate according to different redundancy??
External redundancy:

for external redundancy, we should atleast have diskspace of 5.5GB and 1 disk required for redundancy in OCR diskgroup
Normal redundancy:

For normal redundancy, we should have atleast 11GB diskspace and 3 disks required for redundancy in OCR diskgroup

High redundancy:

For high redundancy, we should have atleast 16.5GB diskspace and 5 disks required for redundancy in OCR diskgroup !!

keep in mind that for 12c grid version,we require below for OCR diskgroup configuration
external – minimum 5.5G disk space with 1 disk or more
normal – minimum 11G disk space with 3 disk or more
high – minimum 16.5G disk space with 5 disk or more