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Re: dd: error reading '/dev/sr0': Input/output error




On Monday 10 December 2018 04:11:28 Jude DaShiell wrote:

> On Mon, 10 Dec 2018, Thomas Schmitt wrote:
> > Date: Mon, 10 Dec 2018 02:45:43
> > From: Thomas Schmitt <scdbackup@xxxxxxx>
> > To: debian-user@xxxxxxxxxxxxxxxx
> > Cc: mickydean@xxxxxxxxxxxxxx
> > Subject: Re: dd: error reading '/dev/sr0': Input/output error
> > Resent-Date: Mon, 10 Dec 2018 07:46:23 +0000 (UTC)
> > Resent-From: debian-user@xxxxxxxxxxxxxxxx
> >
> > Hi,
> >
> > md wrote:
> > > When copying a dvd to file on the harddrive, I'm getting [...]
> > > MD> sudo dd if=/dev/sr0 of=/sdb1/movie.iso
> > > 32596480 bytes (33 MB, 31 MiB) copied, 7.00018 s, 4.7 MB/s
> > > dd: error reading '/dev/sr0': Input/output error
> >
> > Do you see fresh messages in the output of dmesg ?
> > Like
> >
> >   Dec  2 13:56:33 ... kernel: [...] Sense Key : Medium Error
> > [current] Dec  2 13:56:33 ... kernel: [...] Info fld=0x69c0
> >   Dec  2 13:56:33 ... kernel: [...] sr 2:0:0:0: [sr0]
> >   Dec  2 13:56:33 ... kernel: [...] Add. Sense: Unrecovered read
> > error Dec  2 13:56:33 ... kernel: [...] sr 2:0:0:0: [sr0] CDB:
> >   Dec  2 13:56:33 ... kernel: [...] Read(10): 28 00 00 00 69 b8 00
> > 00 40 00
> >
> > What do you get from
> >
> >   xorriso -outdev /dev/sr0 \
> >           -check_media use=outdev \
> >           data_to=/sdb1/movie.udf \
> >           --
> >
> > (It will at least show error messages directly.)
> >
> > Gene Heskett wrote:
> > > Classic slow spinup.
> >
> > After 33 MiB of reading ?
> >
> > (We have a bug in the kernel since 2008 which prevents waiting for
> > the drive to become ready after automatic tray loading. But this
> > causes 0 bytes of read result and lets dd end immediately.)
> >
> > > You can get a better dvd drive
> >
> > Read failures of decaying drives often show surprising
> > success-or-error patterns. Depending on how idvdbackup accesses the
> > drive, its doings might be beneficial.
> > But reading in
> >
> >   http://manpages.ubuntu.com/manpages/bionic/man1/dvdbackup.1.html
> >   "-M, --mirror
> >                  backup the whole DVD"
> >
> > i'd expect it to read sequentiall, like dd does.
> >
> > So more questions to md:
> >
> > - Does a second or third dd run yield success if no dvdbackup was
> > run inbetween ?
> >
> > - Does dvdbackup yield a complete set of files if you let it work
> >   until it ends on its own ?
> >
> >
> > Have a nice day :)
> >
> > Thomas
>
> Why not prefix that dd command with a sudo udevadm settle command and
> only allow the dd command to run on success case?

I was not aware of that utility, from the man page:

udevadm settle [options]
	Watches the udev event queue, and exits if all current events are
	handled.

       --timeout=seconds
        Maximum number of seconds to wait for the event queue to become
	empty. The default value is 120 seconds. A value of 0 will check
	if the queue is empty and always return immediately.

Perhaps there is a place to configure that into k3b, and make a write 
verify work?

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>