Very high system load writing data to SCSI DVD-RAM

From: Oliver Feiler (
Date: Mon Feb 05 2001 - 13:32:16 EST


        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

        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.


Oliver Feiler                                                   PGP key ID: 0x561D4FD2
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