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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,dbe024bebf3e8f53 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2004-01-27 05:45:37 PST Path: archiver1.google.com!news2.google.com!fu-berlin.de!uni-berlin.de!tar-atanamir.cbb-automation.DE!not-for-mail From: Dmitry A. Kazakov Newsgroups: comp.lang.ada Subject: Re: [OT] Spirit - Software failure Date: Tue, 27 Jan 2004 14:53:18 +0100 Message-ID: <4sqc10tcge2tror9b3c41ia4lpga9ihdhl@4ax.com> References: <5d6fdb61.0401260215.1e460bdf@posting.google.com> <40152073$0$322$e4fe514c@news.xs4all.nl> NNTP-Posting-Host: tar-atanamir.cbb-automation.de (212.79.194.116) Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: news.uni-berlin.de 1075211135 25797612 212.79.194.116 ([77047]) X-Newsreader: Forte Agent 1.8/32.548 Xref: archiver1.google.com comp.lang.ada:4904 Date: 2004-01-27T14:53:18+01:00 List-Id: On 27 Jan 2004 03:30:55 -0500, Stephen Leake wrote: >Kilgallen@SpamCop.net (Larry Kilgallen) writes: > >> Detailing the Spirit rover's problems. From: >> http://www.cnn.com/2004/TECH/space/01/26/mars.rovers/index.html >> >> "Trosper said the problem appeared to be that the rover's flash memory >> couldn't handle the number of files it was storing. The jam-up, she >> said, apparently kept Spirit from shutting down properly and performing >> a number of functions that normally originated in its flash memory. >> >> "Scientists are still analyzing the data, she said, but would begin >> deleting unnecessary files to test that theory. >> >> "She pointed out that the scientists had thoroughly tested the rover's >> systems on Earth, but that the longest trial for the file system was >> nine days, half of the 18 days Spirit operated before running into the >> problem." >> -------------------- >> Perhaps this is the first time that a defrag actually fixes something? >> > >Deleting files isn't defrag. This report describes a plain old memory leak. > >Which probably would have been checked for if they had called the >software managing the flash ram a "memory management system" rather >than a "file system"; JPL programmers know they need to check for >memory leaks. But apparently they don't know they need to check for >full disks? > >How long does a test need to be to be "thorough"? Longer than 9 days, >apparently :). > >I doubt using Ada would have fixed this. They'd have just mapped >Ada.Text_IO to the flash memory, and had the same problem :). > >Hiding dynamic memory management under a file system metaphor is a bad >idea in so many ways ... Almost as bad as not to use Ada... (:-)) -- Regards, Dmitry A. Kazakov www.dmitry-kazakov.de