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Date:      Sat, 18 Nov 1995 10:45:07 +0500 (GMT+0500)
From:      "Serge A. Babkin" <babkin@hq.icb.chel.su>
To:        terry@lambert.org (Terry Lambert)
Cc:        terry@lambert.org, hackers@freebsd.org
Subject:   Re: NFS benchmarking: iosize granularity?
Message-ID:  <199511180545.KAA09756@hq.icb.chel.su>
In-Reply-To: <199511171729.KAA05706@phaeton.artisoft.com> from "Terry Lambert" at Nov 17, 95 10:29:26 am

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[...]

> > May be. Actually I have experimented with a SCO client mounting FreeBSD disks
> > with different [rw]size and executing dd with different block sizes. The
> > numbers I got are:
> > 
> > [rw]size=8192 dd bs=100k: 150K/s write 705K/s read
> > [rw]size=8192 dd bs=1k:   122K/s write 705K/s read
> > [rw]size=8192 dd bs=512:   28K/s write 688K/s read
> > 
> > [rw]size=2048 dd bs=100k:  53K/s write 316K/s read
> > [rw]size=2048 dd bs=1536:  40K/s write
> > [rw]size=2048 dd bs=1234:  33K/s write
> > [rw]size=2048 dd bs=1025:  28K/s write
> > [rw]size=2048 dd bs=1k:    52K/s write 307K/s read
> > [rw]size=2048 dd bs=512:   28K/s write
> > 
> > [rw]size=1024 dd bs=100k:  27K/s write 691K/s read
> > [rw]size=1024 dd bs=1k:    27K/s write 690K/s read
> > [rw]size=1024 dd bs=512:   28K/s write 651K/s read
> > 
> > With DOS Tsoft's client I got 12K/s write and 200K/s read independently of 
> > [rw]size when testing with sysinfo (I'm not shure was it Norton's or 
> > PC-tools).
> 
> I think you will find that the optimal write size for an NetBIOS based
> NFS client will be 512 bytes because of the way DOS does file I/O.
> 
> For Win95, the optimal size will be 512b, followed closely by 32k
> (32k is highly typical of VFAT).
> 
> I would be extremely iterested in your SCO/FreeBSD numbers for 4096, as
> opposed to 8192 or 2048.  4096 is the natural page size for both systems
> and would seem the correct and logical choice, barring use of NE2000 or
> similar network cards with an imbalance in read/write buffering in the
> FreeBSD driver itself.

OK:

[rw]size=4096 dd bs=100k:  90K/s write 415K/s read
[rw]size=4096 dd bs=1k:    89K/s write 415K/s read
[rw]size=4096 dd bs=512:   27K/s write 403K/s read

[rw]size=512 dd bs=100k:   14K/s write 143K/s read
[rw]size=512 dd bs=1k:     14K/s write 142K/s read
[rw]size=512 dd bs=512:    14K/s write 139K/s read

These numbers are very like DOS, huh ?

> > The network was Ethernet, all network cards are 3c509B except the on in SCO
> > server which was 3c579. The DOS client was connected through a 3COM TP hub,
> > FreeBSD and SCO are on thin Ethernet.
> > 
> > The results are looking like there is some problem with write requests of
> > 512 bytes size.
> 
> What is the FS block and frag size on the boxes?

FreeBSD has bsize=8192 fsize=1024. SCO box has EAFS and HTFS filesystems, 
I cannot get the exact values for them but it looks like fsize=512 and 
bsize=8192 or fsize=1024 and bsize=16384.

Fro write test I have done:

[On FreeBSD] rm /tmp/xxx
[On SCO    ] time dd if=/unix of=/mnt/xxx bs=NNN 
[       or ] time dd if=/usr/bin/perl of=/mnt/xxx bs=NNN

I have copied /unix (about 2.6M) for fast transfers and /usr/bin/perl (about
500K) for slow transfers, I tried to copy /unix for slow transfer too but
the throughput were the same.

For read test I have done:

[On FreeBSD] dd if=/dev/zero of=/tmp/xxx bs=100k count=100 [once]
[On SCO    ] time dd if=/mnt/xxx of=/dev/null bs=NNN

> It could be that the FS can only do I/O in units of 1k?

May be...

		Serge Babkin

! (babkin@hq.icb.chel.su)
! Headquarter of Joint Stock Commercial Bank "Chelindbank"
! Chelyabinsk, Russia



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