Re: performance of san-disk

From: Holger.VanKoll@SWISSCOM.COM
Date: Wed Nov 13 2002 - 06:03:14 EST


uuuhhh.... quite a bit more. did you change any default-values?
 
could you be so nice to post
lsattr -El fcs0
lsattr -El fscsi0
lsattr -El one_of_your_discs
 
did you measure this 70mb/s with my script or in another way?
 
thank you very much!
 

        -----Original Message-----
        From: Willeat, Todd [mailto:TWilleat@MHP.SMHS.COM]
        Sent: Tuesday, November 12, 2002 11:52 PM
        To: aix-l@Princeton.EDU
        Subject: Re: performance of san-disk
        
        
        I've been able to get >70MB/s between a B80 (w/2 CPUs and 2
6228s) and a HDS 9200.

                -----Original Message-----
                From: Holger.VanKoll@SWISSCOM.COM
[mailto:Holger.VanKoll@SWISSCOM.COM]
                Sent: Tuesday, November 12, 2002 3:05 PM
                To: aix-l@Princeton.EDU
                Subject: performance of san-disk
                
                

                Hello,

                I got a p670 connected to HDS (Hitachi; 9900) Storage
with 2 FC-adapter.

                No matter how much disks I access concurrently, I get
34mbyte/sec maximum.
                All 4 CPU are 0% idle when measuring, but depending on
the # disks they spend more time in kernel than in wait.

                # disks accessed kernel wait disk-busy
(topas) transfer Mbyte/sec
                10-20 8 90 50-70%
25
                30 40 60 40-60%
33
                40 55 45 60-80%
33
                50 70 30 40-60%
34
                60 78 22 35-50%
34

                This looks like my CPU-power is the bottleneck, correct?

                As I get 184 Mbyte/sec with the 4 internal disks and 60%
kernel / 40% wait that looks to me as if the fibre-channel driver
(kernel-time) uses all my cpu. Is this correct?

                If someone likes to do some measurement to have numbers
to compare, here is the script I used:

                #!/bin/sh
                #dlmfdrv4 - 61
                count=2000
                bsk=256k
                dev=dlmfdrv
                #dev=hdisk

                start=4
                end=54

                i=$start
                until false
                do
                dd </dev/$dev$i >/dev/null bs=$bsk count=$count
2>/dev/null &
                [ $i = $end ] && break
                let i=i+1
                done

                I would appreciate any other "benchmark"-results,
especially latest ssa-technology and non hds (f.e. ibm) storage servers.

                Regards,

                Holger



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