Re: Odd problem with sha1sums

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

On Sunday 17 September 2006 13:25, Nils Breunese (Lemonbit Internet) wrote:
>Gene Heskett wrote:
>>> Actually I'm not really sure running sha1sum on the device should
>>> give the same sum as running it on the iso file. I believe the
>>> standard procedure is to run sha1sum on the iso after you've
>>> downloaded it and then check the outcome. Did you do that?
>> Yes.
>And did the sha1sum of your download match the sha1sum published?
Sure did Nils, I thought I had indicated that.  And, by using my method of 
finding out how many 2048 byte blocks there are in the file, and then 
asking dd to fetch that many from the disk & pipe it to sha1sum, and those 
results also match.

I believe the real problem of the erronious failure occurs because 1) dma 
is in use, and 2) with dma in use, file length accuracy gets lost in the 
dma buffering.  This is alleviated if you just ask the disk for exactly 
that many bytes, and then the sha1sum is ok.

Is this clear now?

>Nils Breunese.

Cheers Nils, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author) and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2006 by Maurice Eugene Heskett, all rights reserved.

fedora-legacy-list mailing list

[Fedora Development]     [Fedora Announce]     [Fedora Legacy Announce]     [Fedora Config]     [PAM]     [Fedora General Discussion]     [Big List of Linux Books]     [Gimp]     [Free Internet Dating]     [Yosemite Questions]

Powered by Linux