Re: Poor SCSI drive performance on SMP machine, 2.2.16

[Johan Kullstam]

"paradox3" <[e-mail]> writes:

> I did this:
> 
> date
> dd if=/dev/zero of=TESTFILE bs=1024 count=102400
> date
> sync
> date
> 
> 
> and I gave the time differences from the first to the last
> timestamp.

hmm.  i ran this on my old ppro200 with adaptec 2940uw and ibm
DDRS-39130W drive.

sophia(jk)$ cat foo 
date
dd if=/dev/zero of=TESTFILE bs=1024 count=102400
date
sync
sync
sync
date

i get

sophia(jk)$ time bash foo
Sun Jan 28 18:41:52 EST 2001
102400+0 records in
102400+0 records out
Sun Jan 28 18:42:11 EST 2001
Sun Jan 28 18:42:13 EST 2001

real    0m20.803s
user    0m0.400s
sys     0m8.780s

and this during a full kernel compile.

i get similar decent results using my other computer with a symbios
8751sp and fujitsu and seagate drives.

something must be messed up in a configuration somewhere.  are you
sure you are running the drive in synchronous ultra wide mode?  is you
termination good?

> Regards, Para-dox ([e-mail])
> 
> 
> 
> ----- Original Message -----
> From: "Bruce Harada" <[e-mail]>
> To: "paradox3" <[e-mail]>
> Cc: <[e-mail]>
> Sent: Sunday, January 28, 2001 2:31 PM
> Subject: Re: Poor SCSI drive performance on SMP machine, 2.2.16
> 
> 
> >
> > Hm. As a point of comparison, I use a similar system to yours (full SCSI,
> > though, no IDE) and I can copy a 100MB file from disk-to-disk, or on the
> > same disk, in around 13 seconds. Where are you copying to the SCSI drive
> > from - the same drive, an IDE disk, CDROM? If IDE, what are its
> > particulars? (Check with hdparm -iI /dev/hd?)
> >
> > --
> > Bruce Harada
> > [e-mail]
> >
> >
> >
> > On Sun, 28 Jan 2001 12:44:29 -0500
> > "paradox3" <[e-mail]> wrote:
> > >
> > > I don't get any messages relating to the drives in any syslog output.
> > >
> > > >
> > > > Do you get messages like the ones below in /var/log/messages?
> > > >
> > > >   sym53c875-0-<0,0>: QUEUE FULL! 8 busy, 7 disconnected CCBs
> > > >   sym53c875-0-<0,0>: tagged command queue depth set to 7
> > > >
> > > > In fact, do you get any messages in your log files that look like they
> > > > might be related?
> > > >
> > -
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> >
> 
> -
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-- 
J o h a n  K u l l s t a m
[[e-mail]]
Don't Fear the Penguin!