remo strotkamp wrote:
>
> bug1 wrote:
> >
> > Clay Claiborne wrote:
> > >
> > > For what its worth, we recently built an 8 ide drive 280GB raid5 system.
> > > Benchmarking with HDBENCH we got 35.7MB/sec read and 29.87MB/sec write. With
> > > DBENCH and 1 client we got 44.5 MB/sec with 3 clients it dropped down to about
> > > 43MB/sec.
> > > The system is a 600Mhz P-3 on a ASUS P3C2000 with 256MB of ram, the raid drives
> > > are 40GB Maxtor DMA66, 7200 RPM, and each is run as master on its own channel.
> > >
> > > Turning on DMA seems to be the key. Benchmarking the individual drives with
> > > HDBENCH we got numbers like 2.57MB/sec read and 3.27MB/sec write with DMA off
> > > and it jumped up to 24.7MB/sec read and 24.2MB/sec write with it on.
> > >
> > > That, and enough processing power to see that paritity calc is not a
> > > bottleneck.
> > >
> >
> > Can you use your raid system with DMA turned on or do you get irq
> > timouts like me ?
>
> gonna jump on the bandwagon here...:-)
>
> How often do you get them?? On all the disks, or just
> some of them. In all the modes or just with ultra66???
>
> i get some every couple of days, normally resulting in
> the dma getting disabled for the specific drive...:-(
>
> but the filesystems seem to be ok...
>
> remo
Yea, i get them on my disks (Quantum XA and KX, both my IBM DPTA
372050), they usually start at the last ide channel and work backwards.
In the last 24 hours ive been getting them when e2fsck runs after
rebooting. Usual cause of rebooting is irq causeing lockup, or endlessly
trying looping trying to get an irq.
Im convinced its my hpt366 controller, ive mentioned my problem in a few
channels, no luck yet.
I used to think it was the raid code, but i get it with lvm as well, it
happens more often from reading than writting via the HPT366, the more
load placed on the controller the more likely it is to lockup, one drive
by itself it just losses interrupts (sometimes it can recover), if use
three or four channels, using both my onboard hpt366 and my pci card it
locks up hard in a fraction of a second
I want to try and work this problem out, im not a kernel hacker though.
Anyone have any advice on how to get into kernel debugging, i know c, i
dont know the kernel though. I know how to use ksymoops thats about it.
Glenn
