On Wed, 9 Feb 2011, Thomas Schmitt wrote:
Hi, Mark Weyer in Bug#420716:Use case: I bought Debian DVDs from a vendor. [...] the isos are padded when written to the medium.How much padding was applied relative to the image ? Just up to the next full 32 KiB ?
It does not (=should not) matter. For reference, we've been padding a fixed amount of 300 kB ever since the buggy early kernels could not reliably read the last sectors of the filesystem.
32 KiB alignment is a technical necessity with DVD. With BD it is 64 KiB. jigdo-dvd/debian-6.0.0-amd64-DVD-1.jigdo tells me that the image size is 4662140928 = 142277.25 * 32 * 1024. Shall we strive for aligning the image size for DVD and BD ?
Should not be necessary these days. The burning software and burner firmware should handle all necessary padding issues for each different medium format. (For example, they should always support burning businesscard isos to BD.)
In any case, please make sure that the isosize always equals the .iso file size.
Best regards, Anne Bezemer