Bug#887619: mount: no medium found on /dev/sr0

[shivgupta]

Package: cdrom
Severity: normal

Dear Maintainer,

CD/DVD is not mounted

mount /dev/sr0 /mnt/iso/ gives following message

mount: no medium found on /dev/sr0



-- System Information:
Debian Release: 9.3
APT prefers stable
APT policy: (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 4.9.0-4-686-pae (SMP w/4 CPU cores)
Locale: LANG=en_IN, LC_CTYPE=en_IN (charmap=UTF-8), LANGUAGE=en_IN:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

[Steve McIntyre]

On Thu, Jan 18, 2018 at 07:17:23PM +0530, shivgupta wrote:
>Package: cdrom
>Severity: normal
>
>Dear Maintainer,
>
>CD/DVD is not mounted
>
>mount /dev/sr0 /mnt/iso/ gives following message
>
>mount: no medium found on /dev/sr0

This is a very vague report, and almost definitely "cdrom" is not the
place you meant to report this - that's an alias for handling errors
with Debian installer media.

If you need help, more information is needed, at the very least:

* Did you have a disc in drive sr0?
* Was it spun up?

--
Steve McIntyre, Cambridge, UK. st...@einval.com
"Yes, of course duct tape works in a near-vacuum. Duct tape works
anywhere. Duct tape is magic and should be worshipped."
-― Andy Weir, "The Martian"

[Debian Bug Tracking System]

Your message dated Thu, 18 Jan 2018 14:37:46 +0000
with message-id <20180118143746....@tack.einval.com>
and subject line Re: Bug#887619: mount: no medium found on /dev/sr0
has caused the Debian Bug report #887619,
regarding mount: no medium found on /dev/sr0
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact ow...@bugs.debian.org
immediately.)


--
887619: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=887619
Debian Bug Tracking System
Contact ow...@bugs.debian.org with problems

[Thomas Schmitt]

Hi,

shivgupta wrote:
> > mount: no medium found on /dev/sr0

Steve McIntyre wrote:
> * Did you have a disc in drive sr0?
> * Was it spun up?

The first question was my first thought, too.
But it's not about the drive spinning up, but rather the 10 to 15 seconds
it normally needs to inspect the medium.

So: Was the medium already loaded and the drive stopped blinking ?
If the drive cannot blink: Did you wait 30 seconds after loading ?

If the tray had to be loaded by the mount command, then the affected
package is the Linux kernel. The regression that automatic tray loading
shows not enough patience was introduced somewhere between 2.6.18 and
3.16.

(My theory is that in drivers/scsi/scsi_lib.c the loop under
/* try to eat the UNIT_ATTENTION if there are enough retries */
once had some own sleep action but now quickly performs three SCSI
commands TEST UNIT READY and then gives up.
Or maybe the code in drivers/scsi/sr.c under
/* let's see whether the media is there with TUR */
once was a loop which retried if the was "not ready".)


Have a nice day :)

Thomas