When you use the -i (inspect) option on the BRU command line, BRU reads the archive tape and verifies the checksums of the data written. If data or internal storage structures are inconsistent, BRU will issue warning messages. You can stack -i with -c to manually inspect the backup that is run:
bru -c -i
This will back up all files in the current directory, then rewind and do a checksum verification of the archive. This is the equivalent of BRU’s AUTOSCAN mode, and is not required unless you have disabled the AUTOSCAN feature with the -A command line option or defined noautoscan in the /etc/brutab for the specific device.
You can tell BRU to inspect an archive at any time. Unlike the -d option described later in this chapter, the files used to create the archive do not need to be on line.