On 04/01/2015 11:40 PM, Robin Laing wrote: > On 2015-04-01 19:15, g wrote: >> On 04/01/2015 02:18 PM, jd1008 wrote: >>> After burning 3 DVD's, and reading them back to compute sha256sum. >>> all three of them generated these error messages during readback, >>> and all 3 messages show the error was past the 4gb offset. >>> >>> Is this a media issue or is it the burner? >> >> 1- burn dvd at 2 speeds lower than what you used and had failure. >> >> if ok, problem is either burner or blanks. >> >> 2- burn dvd at failure speed on a different burner. >> >> if ok, get a new burner. if failure, may be blanks. >> >> 3- try different program or burn from command line. >> >>> A side question: why does the block io layer assume that all media >>> have 512 byte sectors? >> >> i believe that is a carry over from disk formatting started by the >> IBM PC. [do not hold me to that] >> > > Also watch power supply voltages. > > I have ran into two power supplies that caused issues with CD > burning. Couldn't supply that little extra bit of current during > the burn process. To burners later, I finally found it. this is true. a few years back, a poster asked for recommendations on building up system and had a lot of responses. my response of getting a power supply with at least a 20% factor, and that a 30% factor would be even better due to my considering future additions or changes. i was met with opposition and even ridicule from a poster who stated that he had never seen need. too many 'builders' are unaware of such factors and will end up with a system that gets flaky when additions and upgrades are made. such is a prime reason for 'ready made' failures. back to dvd checksum errors and a great surprise that i just had. due to need for centos 6.6 i386 for a system that i am putting together for home control use, i decided to burn the iso to a dvd rw disk using k3b and all went well including k3b ok'ing the burn. after closing k3b i ran 'sha256sum /dev/sr1 > sr1' with disk still in the usb drive i burned it with. checksum failed. so decided to moved disk to the internal burner to see how it check. 'sha256sum /dev/sr0 > sr0' produce correct sha256sum. having run check on the usb burner many time before when using k3b and cl and i have gotten good checks, i was surprised. am i going to worry about it. hell no. 2 out of 3 good checks tells me that Murphy is at it again. ((GBWG)) -- peace out. in a world with out fences, who needs gates. CentOS GNU/Linux 6.6 tc,hago. g . -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
