From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,1101264a9f24d62d X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!newsread.com!news-xfer.newsread.com!logbridge.uoregon.edu!xmission!news.utah.edu!newsfeed.cs.utexas.edu!geraldo.cc.utexas.edu!not-for-mail From: bdbryant@mail.utexas.edu (Bobby D. Bryant) Newsgroups: comp.lang.ada Subject: Re: Wiping a disk clean Date: Thu, 4 Aug 2005 11:32:04 +0000 (UTC) Organization: dis- Message-ID: References: Reply-To: bdbryant@mail.utexas.edu NNTP-Posting-Host: dial-a-128-83-253-135.telesys.its.utexas.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: geraldo.cc.utexas.edu 1123155124 29 128.83.253.135 (4 Aug 2005 11:32:04 GMT) X-Complaints-To: abuse@utexas.edu NNTP-Posting-Date: Thu, 4 Aug 2005 11:32:04 +0000 (UTC) X-Newsreader: knews 1.0b.1 Xref: g2news1.google.com comp.lang.ada:3952 Date: 2005-08-04T11:32:04+00:00 List-Id: On Tue, 02 Aug 2005, Larry Hazel wrote: > If I create a binary file, use sequential_io to write records of all > ones until Use_Error is raised. Then, delete the file and repeat with > all zeros. > Will the unused portion of the disk be wiped clean so that no one could > recover what was written there before? Modulo the caveats a couple of others have already mentioned re partially used allocation units, it would be easier and probably more effective to repeat $ cat /dev/random > temp.dat ; rm temp.dat a few dozen times. As I understand it, the need for repetition comes from the fact that a drive wobbles somewhat during use, so whenever you overwrite a sector it may leave a "fringe" of the earlier data to one side or the other of a track. -- Bobby Bryant Austin, Texas