Hi,
After reading through the btrfs documentation I'm curious to know if
it's possible to ever securely erase a file from a btrfs filesystem (or
ZFS for that matter). On non-COW filesystems atop regular HDDs one can
simply overwrite the file with zeros or random data using dd or some
other tool and rest assured that the blocks which contained the
sensitive information have been wiped. However on btrfs it would seem
any such attempt would write the zeros/random data to a new location,
leaving the old blocks with the sensitive data intact. Further, since
specifying NOCOW is only possible for newly created files, there seems
to be no way to overwrite the appropriate blocks short of deleting the
associated file and then filling the entire free filesystem space with
zeros/random data such that the old blocks are eventually overwritten.
What's the verdict on this?
Regards,
Kyle
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
