'Operation not permitted' error seen with private/var/db folders in BigSur

I am currently working for a Data Protection software solution. While backing up <private/var/db> folders using our product, there were issues with accessing <private/var/db> folders and backup of those fails with error 'Operation not permitted' .

I have provided 'Full Disk Access' permission to my application.

Error 'cannot open dir "." Operation not permitted' occurs for following folders.

(/System/Volumes/Data/private/var/networkd/db/):
(/System/Volumes/Data/private/var/db/appinstalld/): (/System/Volumes/Data/private/var/db/installcoordinationd/)
(/System/Volumes/Data/private/var/db/oah/)
(/System/Volumes/Data/private/var/db/lockdown/)(/System/Volumes/Data/private/var/db/DifferentialPrivacy) (/System/Volumes/Data/private/var/db/MobileIdentityService/)
(/System/Volumes/Data/private/var/db/searchparty/)
(/System/Volumes/Data/private/var/db/SystemKey)
(/System/Volumes/Data/private/var/db/DifferentialPrivacy)

(/System/Volumes/Data/private/var/protected/trustd/private/)

I have following questions:

1) What does above directory contains?
2) Why even with 'Full Disk Permission'( provided for my application), 'Operation not permitted' error is seen?.
3) Can these directories be excluded from backup?



'Operation not permitted' error seen with private/var/db folders in BigSur
 
 
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