[lug] RH Linux download + hdparm
Calvin Dodge
caldodge at fpcc.net
Thu Oct 18 14:52:29 MDT 2001
On Thu, Oct 18, 2001 at 08:03:04PM +0000, Greg Horne wrote:
> DMA = 0
> Timing buffered disk reads: 64 MB in 13.35 seconds = 4.79 MB/sec
> DMA = 1
> Timing buffered disk reads: 64 MB in 6.75 seconds = 9.48 MB/sec
That's verra nice!
> Major improvment on my K6! Slowed down the Pentium 200 by 1.07 MB/sec.
> Does the DMA setting stay after running hdparm or do I have to make it
> permanent elsewhere? Thanks for all the info Calvin!
One does one's best.
I believe the setting stays until 1) a driver error, or 2) rebooting. Check out the hdparm manual (option "-k" in particular) to see about preserving the DMA setting during error recovery.
To make it permanent after rebooting ...
IIRC, old RH distros didn't have any pertinent configuration options built in (or maybe I just wasn't aware of them at the time - I've been using RH for about 3.5 years, so I was a Linux newbie when I first installed RH 5.1). On those systems I'd put the appropriate hdparm command in /etc/rc.d/rc.local.
At some point that config info WAS built in - the file /etc/sysconfig/harddisks was the place to go to set such hard drive options.
I _believe_ current kernels set DMA by default.
So ... what distro, version and kernel are you using?
Calvin
--
Calvin Dodge
Certified Linux Bigot (tm)
http://www.caldodge.fpcc.net
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