Ryan Underwood - 2002-12-22


Here is an odd problem.  I hope somebody has a clue what could be happening.

I have a 8X Sony Spressa CRX140S and a Plextor 40X Max both connected to a Symbios 83c875 ultra-scsi controller.  Kernel is 2.4.19.  cdrdao version is 1.1.7.

When copying "certain" discs, (not all discs), in disc-at-once mode on the fly, it seems that eventually the Plextor reader gets bored and spins down.  What I mean by this, is that the burner keeps going, and the lights on the Plextor drive would appear that it is still reading, but I can audibly hear it park the CD, and immediately the buffer begins to dwindle on cdrdao for an eventual underrun.  It is like the Plextor drive knows that it should be reading data, but the disc is stopped anyway.

If I increase the buffer size to 256 for example, it takes up to a minute for the underrun to occur once the disc stops being read, but it still eventually happens.

I know the Plextor drive is not having trouble reading these discs; I have dd'd the whole thing to /dev/null without a single hiccup, and I have done readcd -c2scan without any errors on the given disc.

Here's the kicker.  If I hear the drive spin down, and immediately open up an xterm and cat /dev/cdrom, the drive spins back up and the cat returns an I/O error (presumably because the drive is already in use?)  But then the buffer fills back up in cdrdao and it progresses as if nothing happened!  Also, even if I already did this once in a recording session, eventually the drive gets "bored" again and has to be woken up in this manner.  (??????????)

I have checked the timeout on the drive with plextor-tool and it is set to 2min.  I don't see how this would be the problem, as the drive is being continuously read from.

This setup has been solid and stable for years since I had these drives.  Only recently have I had this problem.

Any clues?

P.S.  Can a command line switch be implemented to lock the tray closed of whatever the --source-device is?