Re: [9fans] Writing device drivers

[quanstro@quanstro.net]

i didn't know if there was something i didn't know.

about five years ago i built a pretty large (for the day) oracle database (2TB) with a quad
processor va linux box (running linux, oddly enough) and three three-channel
dac960 raid cards.  each channel was connected to a simple raid cabnet with 8 36G
drives in a raid-5 setup.  the whole thing at the time was about $125k and it ran
circles around the ibm big iron it replaced.  we had no problem keeping the load above
0.5per processor and the disk io limited by pci bandwidth.

the only problem we had was when the development server took several power cycles
and a nearby lightning strike.  although the system was on a ups, i had to manually
remind each card about it's attached arrays.  but we didn't loose a byte.

today, i think one could get a lot more bang/buck with (s)ata drives and lvm2 striping/raid 5.
then again, much of the data was documents stored by md5 score.  it would have been great
to have fossil back then.

- erik

On Tue Apr 18 23:03:07 CDT 2006, jmk@plan9.bell-labs.com wrote:
> i have no idea if it's a poor piece of hardware or not, i just
> can't see me ever wanting to use one.
>
> On Tue Apr 18 23:12:50 EDT 2006, quanstro@quanstro.net wrote:
> > am i missing something?  is this a poor piece of hardware?
> >
> > - erik
> >
> > On Tue Apr 18 10:43:14 CDT 2006, jmk@plan9.bell-labs.com wrote:
> > > 	>What is a dac960?
> > >
> > > it's a raid controller formerly made by mylex and now made by lsilogic.
> > > it might even originally be made by american megatrends, i'm not sure.
> > > i found one recently and threw it in the pile of cards i'll never have
> > > a driver for (nor see the need to ever write a driver for).