NetBackup database is not supported on the btrfs file system
The installation of the NetBackup database on a btrfs file system is not supported. Do not attempt to install the NetBackup database onto a btrfs file system. The database files reside on the primary server in the directories under /usr/openv/db. Before you attempt a NetBackup upgrade, move the database to a supported file system (such as ext4 or xfs) before you start the upgrade. More information about moving the database before an upgrade is available in the NetBackup Upgrade Guide.