Hi Greg, On Mon, Oct 03, 2005 at 05:26:39AM -0500, greg wm wrote: > hi, > > i'm surprised and annoyed to find that my backup linux server fails to > compute a md5sum properly about every 3rd time i check a CD image. so i > guess that machine can't add, and i guess i don't really want it as my > backup server afterall! My guess would be the problem lies in the CDROM drive or disk that it burned and compatibility with other drives. > but waitaminute, how do i really know it's hardware? i can imagine a > software bug that is latent enough to only surface on occational > machines. how would you test such a bugger to see what's going on? A single md5sum on a complete CD doesn't tell you much. Try md5sum on each file on the CD, or create a binary diff program that will tell you how much(and where) the data differs. > and then good grief, my XP machine.. i burned from it, the CD is fine, > but cygwin sha1sum always fails the iso. somehow this one doesn't seem > so likely to be hardware, but how would i know? what tests would you run? > > in an earlier life, before many of you were born i'm sure, working on > data general clones my (then) company (kurzweil computer products) was > building, i discovered (guess how) that the hardware could be shown to > fail only when stressed with certain patterns passing via DMA while > simultaneously testing memory. i had to write the diagnostic to prove > it. i wasn't immediately popular with our hardware designers, but the > test became standard in QA. in the intervening 3 decades it seems i > have been blessed with working on hardware that just works. but now.. > my current life won't afford me the luxury of writing my own diagnostics. Go for it, programming/scripting is fun! > are there some good open source diagnostics that stress the machine > fully, like in particular stressing disc DMA while simultaneously > testing memory? > > tia, > greg > > Greg Whitley Mott > IT Coordinator > NonviolentPeaceforce.org > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > tclug-list at mn-linux.org > http://mailman.mn-linux.org/mailman/listinfo/tclug-list >