On Mon, Aug 25, 2008 at 10:23:14PM -0700, Neko wrote:
> other note jonathan the box im using doesnt support the whole drive,
> but bsd's kernel doesnt once its loaded, i fear the rawdevices would
> bring me back to the unsupported drive in bios issue,
>
> would raw dev use my bios's specs, or the bsd's specs,
>
> ill peek at the src, but if someone could comment that..
Sure.
1) You should start with following advice people give you here.
-Otto
>
>
> cheers !
>
> neko
>
> --- On Mon, 8/25/08, Jonathan Gray <[EMAIL PROTECTED]> wrote:
>
> > From: Jonathan Gray <[EMAIL PROTECTED]>
> > Subject: Re: dd performance question
> > To: "Neko" <[EMAIL PROTECTED]>
> > Cc: misc@openbsd.org
> > Date: Monday, August 25, 2008, 11:24 PM
> > On Mon, Aug 25, 2008 at 06:58:30PM -0700, Neko wrote:
> > > Hi all,
> > >
> > > having a 250 GB drive on a PATA strip using lowest PIO
> > mode (without dma if possible), drive specs show a 8 MB
> > buffer ,
> > >
> > > 2 cases are : on same pata strip, one on each strip,
> > >
> > > important to note that the booted drive is the
> > if's straight up to my slave.
> > > (yea i know ill have to run fsck afterwards since itll
> > think it still mounted)
> > > and having no user but su himself.
> > >
> > > i had ran mine at 4mb block space thinking ill use the
> > 16mb bus transfer
> > > divided at most in 4, per second, but i achieved that
> > in a minute instead.
> > > this is really poor performance, 3 days for 250gb
> > transfer at 4mb bs
> > >
> > > dd if=/dev/wd0c of=/dev/wd1c bs=4m
> >
> > This hits the buffer cache, use raw devices for anything
> > apart
> > from mounting, ie /dev/rwd0c
