[ringzero] Re: DVD burner and I/O bottleneck
- From: ed <ed@xxxxxxx>
- To: ringzero@xxxxxxxxxxxxx
- Date: Sat, 3 Jun 2006 13:52:44 +0100
On Fri, 2 Jun 2006 23:12:59 +0200
Godwin Stewart <gstewart@xxxxxxxxxxx> wrote:
> This is where the plot thickens. There have been reboots since the ISO
> image was created so nothing was in the cache when I ran these tests.
You don't need to reboot, just run this bit of C to fill the memory
(pref as root):
http://www.usenix.org.uk/_point.2006-04#gobblemem.c
I know you said you had 1gig of memory, but it's not likely that the
whole disk image would be stored in a contiguous chunk, the moment the
first few blocks are over written, the remaining memory becomes useless
since the image has to be processed in a sequential order, and if it
was over written as memory is low, the chances are that the remainder
has to be reprocessed likewise.
I think the problem may be related to lack of buffer on the burner
itself.
Do you get similar problems writing a 52x CDR (I know it's not as fast
as the 8xDVD, but it's somewhere around there)?
Also, do you by any chance have a gib ethernet that you can push some
data through to see how your PCI bus handles?
Which chipset do you have, and are you using the appropriate kernel
modules/drivers?
I assume your drives can handle the datatransfer rate, but hdparm might
suggest otherwise, if they're particularly old, but I doubt a person
with DVD ISOs would put up with that.
--
Regards, Ed :: http://www.linuxwarez.co.uk
just another perl person
:%s/Open Source/Free Software/g :: Free DNS available
--
You are receiving this message as part of your subscription to the
"ringzero" mailing list at freelists.org. To unsubscribe, send an e-mail
to ringzero-request@xxxxxxxxxxxxx?subject=unsubscribe
Other related posts:
