Re: What pulls in the tray of my /dev/sr1 ?

[Stuart Longland <stuartl@longlandclan.yi.org>]

Hi Lisi,
On 04/08/15 08:43, Lisi Reisz wrote:
> On Monday 03 August 2015 23:39:48 Stuart Longland wrote:
>> On 28/07/15 22:58, Thomas Schmitt wrote:
>>>> The delay seems a bit long for such an action though.
>>>
>>> My measurements were all between 197 and 200 seconds.
>>> With some inaccuracy because waiting 3 minutes harms my
>>> reaction time.
>>
>> Silly question, but why does re-loading a disc take more than 197 seconds?
> See the beginning of the thread:
> https://lists.debian.org/1371955517162095769@scdbackup.webframe.org

Yes, I saw the initial post:
> one of my optical drives automatically pulls in its tray if it stands
> out for a few minutes. The four others do not try to byte[sic] my fingers.
> 
> The waiting time between manual tray eject and automatic tray load
> is quite reliably 195 to 200 seconds.

To me, a tray automatically retracting itself after being open for more
than a minute sounds a perfectly reasonable damage-prevention measure.

It prevents dust from settling on the tray, thus getting drawn into the
workings of the drive causing problems.  It prevents the tray itself
being damaged from being bumped whilst being left out.

Finally it discourages the tray's misuse by the illiterate (e.g. as a
carry handle or cup holder).

195-200 seconds seems a more than generous amount of time to allow for
the loading or removal of a disc from the tray, including the time
needed to retrieve the disc or return the disc to its storage cover and
perhaps put that cover back on a shelf.

I can think of two possibilities:

1. This is a built-in feature of the drive for the above reasons, and
would happen regardless of what software stack is running.  (Maybe try
boot up GRUB, break into the command prompt, then try the eject timing
experiment.)

2. Some software on the host periodically 'polls' the drive for disc
insertion status, and this triggers that particular drive to retract its
tray to see if a disc has been loaded (while the others just report 'no
disc').
-- 
Stuart Longland (aka Redhatter, VK4MSL)

I haven't lost my mind...
  ...it's backed up on a tape somewhere.