Subject: Hdparm

From: Dale Ang <[email-masked]>
Date: Mon, 17 Apr 2000 16:37:28 -0700 (PDT)

Seeing as though everyone is comparing their stats, I
would like to add one I tested the other day.

/dev/sda:
Timing buffer-cache reads:   175.34 MB/sec
Timing buffered disk reads:  20.85 MB/sec

This was on a 16MB RAID card, with two 9.1GB Atlas,
mirrored, not striped.

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From: Patrik Schindler <[email-masked]>
Date: Tue, 18 Apr 2000 08:28:39 +0200

>Timing buffer-cache reads:   175.34 MB/sec

Why do you all folks add buffered reads? You are benchmarking your RAM transfer speed, nout your drives with this.

:wq! PoC

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From: Michael Mercier <[email-masked]>
Date: Tue, 18 Apr 2000 00:45:54 -0600

Anyone out there know of a similar command (hdparm) on Solaris?

Mike

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From: Dave Holland <[email-masked]>
Date: Tue, 18 Apr 2000 09:36:11 +0100

> Anyone out there know of a similar command (hdparm) on Solaris?

You could do worse than Bonnie -- http://www.textuality.com/bonnie/

(not really on-topic for netatalk-admins, sorry)

Dave
-- 
      Dave Holland       |      `Who's the departmental expert?'
     Systems Manager     |                 `You are.'
     Incyte Genomics     |                    `Oh.'
      Cambridge, UK      |

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From: Marcus Radich <[email-masked]>
Date: Tue, 18 Apr 2000 20:38:07 +1200

At 8:28 AM +0200 18/4/2000, Patrik Schindler wrote:
>Why do you all folks add buffered reads? You are benchmarking your 
>RAM transfer speed, nout your drives with this.
>
:wq! PoC

We use this to get an idea of the speed of the motherboard in a 
system as we have found that slow motherboards have a profound effect 
on the speed of a server. (We use hdparm as an indication only)

We have seen a system which could get 30MB/sec off the drives, but 
was set up on a cheap motherboard which benched around 22MB/sec. 
Needless to say, it didn't perform well under load. Replacing the 
motherboard with a higher quality board saw it go up to 80MB/sec, and 
the machine performed *much* better. We didn't change the processor 
or the drives.

The largest netatalk-powered site we manage has 15 designers and 10 
admin users with G3s and G4s, all on 100BaseT, connected to a Digital 
Prioris server. This was an WinNT 'upgrade' we performed last year.
Now, this machine has a single Pentium Pro 200 processor plugged into 
a outstanding motherboard (for it's age), which benched over 
100MB/sec. We set up the Mylex DAC960 RAID controller with 4 
Fast/wide drives in a RAID 0+1, and they benched over 26MB/sec. The 
designers are all working off this server, and working with hi-res 
scans! Each mac gets over 9MB/sec, and under load it holds up very 
well. Even with multiple simultaneous accesses, the designers seem to 
be very happy with the speed.

When performing our WinNT upgrades, we always use hdparm to give us 
an idea of how good the motherboard performance is (it's just an 
indication), and how well the drives will go. We can then predict 
whether the system is going to perform well.

mrad01

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"Always ask the question, never assume the answer."
		Marcus Radich 1999

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