GNOME Bugzilla – Bug 125470
Add a "verify CD" after burn feature
Last modified: 2009-07-29 10:46:16 UTC
I find it extremely convenient to generate MD5 checksums for all files on a CD, usually stored in a file called md5sum.txt in the root of the disk. This makes it easy to verify that the contents of a disk are intact any time in the future. At burn time it is of course possible to compare the files on the CD to the files on the hard disk, but later this might not be possible. Having nautilus generate such a file automatically would be quite convenient.
I think it's good and usefull idea to make md5sums.txt file automatically. I think there should be an option (checkbox) "Make checksum of writen files" in "Write to CD" dialog or only in gconf if you don't like to show this option for simple users. It's very simple to generate md5sums.txt - just run this command before writing to cd: find . -type f -exec md5sum {} \; | sort > /tmp/md5sums.txt I don't know if we really need to sort. Also there is one more variant to make md5sums: find . -type f -print0 | xargs -0 md5sum | sort >/tmp/md5sums.txt
This won't be added to nautilus-cd-burner itself, but it should be quite easy to do a stand-alone script to do this: - have the script navigate the whole burn:// scheme - for each normal file, get the "backing file" (the name of the real file) - get the md5sum for that file, and append it to an md5sum.txt file, or whatever, using the relative name inside burn:// (for example, burn:///foo/bar.txt becomes foo/bar.txt in the md5sums.txt) - repeat, and rinse until you've done that for all the files. - then "copy" the file to burn:/// itself - launch the burn. I'll change this bug, however, to allow for the verification of the burnt CD.
*** Bug 147535 has been marked as a duplicate of this bug. ***
*** Bug 149473 has been marked as a duplicate of this bug. ***
*** Bug 324256 has been marked as a duplicate of this bug. ***
How should this be presented in the UI? With a button in the "Write completed" dialog? (four buttons seem too much, to me) A button labelled "Verify"/"Verify disc" would also be cryptic to a non-expert user, IMO. "Verify? Is this CD burning thing a lottery?" :-) Can't this "just work", *asking* to verify only when n-c-b suspects something went wrong? (on frequent burnproof activation? speed variations? queues almost-empty?)
Is this CD burning thing a lottery? Yes, sort of, because of few reasons: 1. There are lots of very cheap CD/DVD-R and CD/DVD-RW media (for example LEAD DATA, PRINCO, etc), which is really low quality (about 10-20% of this media is broken), for more info about this look at CD/DVD-R/RW media tests, e.g. http://www.mscience.com/survey.html 2. Rewritable CD/DVD-RW disks pretty often becomes broken after long use (because of scratch, etc) or frequently writing (depending on CD/DVD disk quality some rewritable disks can become broken after 20-50 rewrites). 3. CD/DVD writers (devices) sometimes records disks with errors, because of various reasons, for example I have one Mitsumi CD writer, which correctly records only about 5-8 disks if I'm recording without an intermission. Notice, that this bugreport is not only about adding a "verify CD" after burn feature, but also about automatical creating checksum files and putting these files into CD/DVD disk before writing. Also automatically adding checksum files into CD/DVD during writing helps people to check in any time if theyr data are correct. This is very important, because D/DVD disks have limited longevity, which can be sometimes very short, for example if CD/DVD disk are leaved on direct sunlight for few hours.
*** Bug 336984 has been marked as a duplicate of this bug. ***
Fabio, please don't change the assignment of the bugs.
Sorry Bastien. In other projects that means "I'm working on this". Is it preferred that I mention that as a comment?
Just add yourself to the CC:, and mention it in a comment, otherwise it makes it hard for people that monitor the maintainer alias to carry on watching the bug.
*** Bug 352173 has been marked as a duplicate of this bug. ***
This has also been requested by an Ubuntu user. The bug report can be found at : https://launchpad.net/products/nautilus-cd-burner/+bug/58254
I would just like to point out that this bug now seems to be tracking the development of several separate features: * The original report asks for a feature that "generates MD5 checksums for all files on a CD, [and stores them] in a file called md5sum.txt in the root of the disk." This is something that I personally have never seen, used, or wanted - but if people want the feature, then that is fine; * One dupe (Bug 147535) and the Launchpad bug ( https://launchpad.net/nautilus-cd-burner/+bug/58254 ) ask for n-c-d to generate md5 sums for CDs. This too, I would have thought, is restricted to the minority who create ISOs. Verification of ISO files against md5 sums doesn't seem to me to have anything to do with burning CDs and quite possibly belongs in a different part of nautilus. I would like to right click ISO and compare it to an md5 file, but I don't think that code belongs in n-c-d; * The topic of most of the "dupes" (Bug 352173, Bug 324256, Bug 149473) is quite a different, much simpler request. Most people seem to be requesting that, once the burn is finished, n-c-d reads the data back off the disc and checks that the files match what was supposed to have been written. This could be implemented by an extra button or, if we were to follow Nero, a checkbox asking whether the user would like to "Verify CD after burning is complete?". This feature, by contrast, is present in every commercial CD burning application that I have used and is the reason that I reboot into Windows for my CD burning. I can't see how these bugs are the same bug. I think that it would be sensible to split them up into separate bugs so that they are dealt with properly; otherwise, one of these features may be implemented and all three will be closed. I am really keen to see the third feature implemented, but every time that I talk to someone about this bug, they tell me that it is about md5s and not about verifying burnt CDs with what was meant to be written.
Just as a further point showing the importance of the difference: I often burn Ubuntu (and other) ISOs. I certainly do NOT want extra files added onto the CD (the proposed md5sum.txt), but I DO want n-c-d to check that the burnt CD matches the ISO file.
Bug 352173 and bug 324256 are both dups of bug 149473. Bug 149473 is not the same as this one, and should not be marked as a duplicate of this one. Somebody authorized, please separate the unrelated bug reports from this one.
*** Bug 153428 has been marked as a duplicate of this bug. ***
*** Bug 561868 has been marked as a duplicate of this bug. ***
I vote *Y*E*S* for ... "once the burn is finished, n-c-d reads the data back off the disc and checks that the files match what was supposed to have been written. This could be implemented by an extra button or, if we were to follow Nero, a checkbox ..."
nautilus-cd-burner has been replaced by Brasero in the GNOME 2.26 release. If your bug still applies to Brasero, please feel free to re-open the bug, and reassign it to brasero itself.