Hi, just reading chattr manpage..
On Monday 18 March 2013 14:15:17 you wrote: > 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? what would chattr +s do? " When a file with the `s' attribute set is deleted, its blocks are zeroed and written back to the disk. Note: please make sure to read the bugs and limitations section at the end of this document. " Nice spring to all of you! :) Mark > > 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 -- Marek Otahal :o) -- 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
