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From: iiitac@swan.pyr (Alan Cox)
Subject: Re: SUMMARY: FreeBSD vs. Linux
Message-ID: <1993Nov18.221856.13769@swan.pyr>
Organization: Swansea University College
References: <CGC6nH.J08@usenet.ucs.indiana.edu> <16C841041BS85.U001295@HNYKUN11.URC.KUN.NL> <2c7g1pE847@uni-erlangen.de>
Date: Thu, 18 Nov 1993 22:18:56 GMT
Lines: 29
In article <2c7g1pE847@uni-erlangen.de> eilts@late.e-technik.uni-erlangen.de (Hinrich Eilts) writes:
>U001295@HNYKUN11.URC.KUN.NL (R. Schalk) writes:
>>Please tell me what you can do in FreeBSD and not in Linux???????
>Reliable networking. I tried Linus on a 386, connected to a NeXT and got:
>NFS, mounted on NeXT:
> NexT --> PC: 131 kB/sec, PC --> NeXT: 548 kB/sec
>NFS, mounted on PC:
> NeXT --> PC: 125 kB/sec, PC --> NeXT: 19 (!) kB/sec
>by copying two 1.4MB files.
>rcp and remote-piping ("rsh 'xx yy' < zz" etc) brokes.
rcp and rsh work fine on pl13r or later, but yes your basic comment stands
the Linux networking is still a little less reliable than BSD, but we are
working on it and things are getting there.
Now your NFS example is a bit sad because its a BSD problem not a Linux
problem. You see Linux is doing NFS in 1K blocks and unfortunately the
BSD(SUN actually I think ?) derived kernel NFS and the low level block
handlers on BSD kernels aren't capable of sensible synchronous IO writes. So
every time Linux does a write BSD and Next goes READ 4 or 8K alter 1K write
4 or 8K synchronous. Since the lowest level drivers could do 1K blocks happily
the problem is the standard kernel nfsd that most people use. This is similar
to the problems with BSD NFS serving PC machines using small block sizes,
or older SYS5.2/3 NFS implementations which also commonly used 1K.
I guess its truer to say that BSD based kernels can't cope with small blocksize
NFS writes very well, while Linux doesn't do so badly. 8-)
Alan
iiitac@pyr.swan.ac.uk