Large .bak file unpacks to empty directory

[andyjpb]

Hi,

I'm trying to unpack the following file that has been generated by a modern version of SQL Server or SAS (I'm not sure exactly how the file was generated).

$ du -hs DB20240718.bak 
338M    DB20240718.bak

$ file DB20240718.bak
DB20240718.bak: Windows NTbackup archive NT, with file catalog, soft size 8*512, software (0x1200): Microsoft SQL Server

with mtftar thus:

$ ../mtftar/mtftar < DB20240718.bak |tar xv
E:
$ ../mtftar/mtftar < DB20240718.bak        
E:   777      0      0           0 14646244777   5634 5ustar0000

...and I end up with a single empty directory:

$ find E\:/
E:/

I've tried various combinations of the command-line options -v, -l, -L, -p, --pax and not managed to get it to unpack any more files.

Do you have any pointers about how I can debug this further?

Thanks for any pointers you can give me.