Each node in a cluster has its own local OCR, called an Oracle Local Registry (OLR), default location is Grid_Home/cdata/$HOSTNAME.olr

crsctl add css  votedisk path
crsctl delete css votedisk path
Voting disks are automatically backed up by Oracle.
If the voting disk is lost or corrupt then recreate by:
  Delete any voting disk on the system
  Add a voting disk – this will automatically insert the backup contents into the new voting disk.

ocrconfig -showbackup
ocrconfig -manualbackup
ocrconfig -backuploc directory-name # (def loc is Grid_Home/cdata/cluster_name/)
ocrcheck # to check the ocr contents

To recover the OCR from a backup:
ocrconfig -showbackup
ocrdump ocr_dump_file_output -backupfile file_name # to review the contents of the backup
crsctl stop cluster -all
ocrconfig -restore file_name #file_name is the name of the ocr file you want to restore
crsctl start cluster -all
cluvfy comp ocr -n all [-verbose] # verify the ocr integrity

ocrcheck -local
ocrdump -local -stdout
ocrconfig -local -import file_name
ocrconfig -local -repair -replace current_olr_file_name -replacement new_olr_file_name # change loc of olr file
ocrconfig  -replace source_olr_file_name -replacement destination_olr_file_name # replace an olr file
ocrconfig -add new_ocr_file_name # Clusterware supports up to 5 copies of the OCR
ocrconfig -delete ocr_file_name # 
ocrconfig -repair -add new_ocr_file_name
ocrconfig -repair -delete ocr_file_name
ocrconfig -repair -replace current_olr_file_name -replacement new_olr_file_name # change loc of olr file