Very high system load writing data to SCSI DVD-RAM

From: Oliver Feiler (kiza@lionking.org)
Date: Mon Feb 05 2001 - 13:32:16 EST

Hello,

        I have the following problem with a DVD-RAM drive. The drive is a
Panasonic LF-D101 connected to a Tekram DC395U SCSI controller. Kernel is
2.2.18 with the patch for the Tekram controller
(http://www.garloff.de/kurt/linux/dc395/).

        When I write huge amounts of data to a DVD-RAM the system load is
getting very high, like 10 or even above and the system temporarily freezes
for a short time every minute or so while writing data to the drive. The DVD
drive writes data with 1.35 MB/sec on the discs so there is not really much
data going over the SCSI controller. Reading data from DVD-RAMs is done with
2.7 MB/s (2x) by the drive and does not cause any problems at all.

        This problem also existed with previous kernels (2.2.16/17) and with
another SCSI controller I had before the Tekram. Adaptec 2904CD using the
aic7xxx driver.

        There is a 4x Teac burner connected to the SCSI controller as well.
Burning CDs does not raise the system load or cause any other problems.

Bye,
Oliver 

-- 
Oliver Feiler                                               kiza@gmx.net
http://www.lionking.org/~kiza/pgpkey              PGP key ID: 0x561D4FD2
http://www.lionking.org/~kiza/
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This archive was generated by hypermail 2b29 : Wed Feb 07 2001 - 21:00:22 EST