Re: [OT] Spirit - Software failure

[Dmitry A. Kazakov <mailbox@dmitry-kazakov.de>]

On 27 Jan 2004 03:30:55 -0500, Stephen Leake <stephen_leake@acm.org>
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?
>>     <GRIN>
>
>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