NFS write() calls lead to read() calls?

Robert Watson rwatson at FreeBSD.org
Wed Mar 28 19:21:02 UTC 2007


On Wed, 28 Mar 2007, Ivan Voras wrote:

> Robert Watson wrote:
>> On Wed, 28 Mar 2007, Ivan Voras wrote:
>>
>>> Ulrich Spoerlein wrote:
>>>
>>>> What kind of C program or script did you have in mind? My C-foo is very 
>>>> weak ...
>>>
>>> If you have python installed, this is a simple way:
>>
>> Also good is dd between the file system and /dev/null.  Something worth 
>> remembering is that some tools (cp(1) in particular) use memory-mapped I/O, 
>> which may behave differently than raw I/O operations.
>
> You mean /dev/zero and dd with notrunc option? Yes, I didn't know about 
> notrunc until now :)

Yes, precisely what you said. :-)

Robert N M Watson
Computer Laboratory
University of Cambridge


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