Re: Burning multiple DVDs at one time

[Wakko Warner <wakko@animx.eu.org>]

Stefan Richter wrote:
> On Mar 15 Wakko Warner wrote:
> > I'm having problems doing this.
> > 
> > When I burn a single disk, wodim shows the drive buf @ 99% consistently. 
> > The instant that a 2nd disk is being burned, the drive buf on the first one
> > starts to drop and data stops when the 2nd wodim is performing OPC.
> > 
> > During the burn of both discs, the drive buf will drop on both until one of
> > them finishes.  Both drives see under runs.
> > 
> > When one starts fixating, the other will hang until the fixation is
> > completed.
> > 
> > During the burns, the fifo of both never drop below 99%
> > 
> > There are no logs that are produced.
> > 
> > My burners are:
> > [6:0:0:0]    cd/dvd  ATAPI    iHAS422   8      4L11  /dev/sr7
> > [7:0:0:0]    cd/dvd  ATAPI    iHAS224   B      GL05  /dev/sr8
> > 
> > Both are SATA drives attached to the onboard sata controller
> > 00:1f.2 SATA controller: Intel Corporation 631xESB/632xESB SATA AHCI Controller (rev 09)
> > 00:1f.2 0106: 8086:2681 (rev 09)
> > 
> > The kernel is a vanilla kernel v3.0.0.  (This also happened with 2.6.35)
> > 
> > I don't believe it matters, but the data is coming over NFS via gigabit
> > ethernet.  Each burn process uses a 768M host buffer.  As I stated, the host
> > fifo on wodim never goes below 99%
> > 
> > The system motherboard is a SuperMicro X7DA8
> 
> This is likely due to serialization by a global mutex in the sr driver.
> Have a look at thread "[PATCH] [SCSI] sr: fix multi-drive performance,
> remove BKL replacement" from February. https://lkml.org/lkml/2012/2/28/230

Thanks.  I looked at the patch.  I would just like to confirm that I can
patch my 3.0.0 vanilla kernel, compile the sr module, unload the current and
load the patched one without the need to reboot.

I do not use udisks.

Thanks for the responce, I'll try this when I have more discs to burn.

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 million bugs.