Re: [Libguestfs] [PATCH nbdkit 2/2] tar: Rewrite the tar plugin (again), this time in C.

> > Does this always work even when the tar file was created with sparse > file support? For that matter, if the tar file was created with > sparse file contents, are we even guaranteed that a contiguous > offset of the tar file is blindly usable as the data to serve? We've used the same technique on thousands of OVA files without hitting any problem so far, so I guess that ... > $ truncate --size=1M large > $ echo 'hi' >> large > $ tar cSf f.tar large > $ ls -l large f.tar > -rw-rw-r--. 1 eblake eblake 10240 Jul 6 13:57 f.tar > -rw-rw-r--. 1 eblake eblake 1048579 Jul 6 13:48 large > $ LANG=C tar --no-auto-compress -tRvf f.tar large > block 0: -rw-rw-r-- eblake/eblake 1048579 2020-07-06 13:48 large > block 2: ** Block of NULs ** > > Yep, we need to special-case sparse tar files :( .. OVAs don't use this feature. I wonder if it's a GNU feature?