Secure deletion with journaling?

Posted Dec 7, 2006 15:04 UTC (Thu) by abatters (✭ supporter ✭, #6932)
Parent article: Secure deletion and trash bin support

According to the man page for 'shred', overwriting a file stored on a journaled filesystem (via normal write() system calls) does not necessarily overwrite the actual data on disk. I do not see how moving a deleted file to a special directory makes it possible to perform a subsequent secure delete if the VFS doesn't special-case it in other ways. This is especially true if the data had been written to blocks in the filesystem that are no longer associated with the file.

OTOH, the man page for chattr does mention a 'data journaling' attribute; maybe you are supposed to turn off data journaling at the same time as setting secure delete (preferably before writing any actual sensitive data to the file). Does anyone know if this flag is honored?

Secure deletion with journaling?

Posted Dec 7, 2006 15:20 UTC (Thu) by zlynx (guest, #2285) [Link] (1 responses)

Overwrite the file with O_DIRECT set? Create a new filesystem flag so that even the most cache-happy journaled FS does the right thing?

Secure deletion with journaling?

Posted Dec 7, 2006 16:52 UTC (Thu) by rvfh (guest, #31018) [Link]

The secure deletion resides in the FS part for sure. Only the undelete part can be in the VFS (just a mv after all).