On 2003-11-23 17:31 +0100, Dag-Erling Smørgrav <[EMAIL PROTECTED]> wrote: > Stefan Eßer <[EMAIL PROTECTED]> writes: > > What I'm suggesting is to have the obliteration implemented as an > > add on to the dirty buffer flush, with the difference that the > > buffer contents is prepared for the next step of the erasure process, > > written out, and then not declared free but again prepared for the > > next overwrite pass. > > This next pass won't be until thirty seconds later, so it'll take > about half an hour to completely obliterate a file. Furthermore,
These 30 seconds are not a universal constant and ISTR. I had in mind, that one obliteration pass is performed. After each pass, a cache flush has to be performed, and the next pass is performed immediately or only after a brief delay. I see, that this may cause too many CPU cycles spent traversing the buffer cache. > unmounting a file system less than half an hour after a file is > deleted or truncated will fail, and shutting down will most likely > leave the file system unclean due to repeated failures to flush the > dirty buffer list. Yes, that's why I meant that fsck might be used to trigger the restart of an erasure process that was not completed due to shutdown or a crash. This does obviously no good in case that somebody else got hold of your disk, menawhile, but it covers cases that are not dealt with by a user-land utility (which would just be stopped halfway through when the system goes down). Regards, STefan _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"