Eberhard Moenkeberg schrieb:
> Hi,
> 
> On Fri, 9 Sep 2005, Robert Schiele wrote:
> 
>> On Fri, Sep 09, 2005 at 03:13:46AM +0200, Carl-Daniel Hailfinger wrote:
> 
> 
>>> I took a look at it and lifted a few ideas. However, --size-only is
>>> not needed when converting from ftp to rsync. rsync will use its
>>> sliding checksum algorithm (NOT the dreaded MD4 checksum) to compare
>>> the files and not redownload them.
>>
>>
>> Sure but this still forces the server to read the full file ftom disk.
> 
> 
> Exactly; it would force the server to behave like with "--checksum" even
> if the server has disabled it.

Except that it needs fewer processor cycles. But I see your point
about server IO bottlenecks.

> There is a special situation when an ftp mirror converts to rsync:
> Via ftp, only crippled and/or "time zone shifted" time stamps are
> available, but rsync communicates true inode time stamp values.
> So here we "know" the file contents are equal but only the time stamps
> not. Best scenario for "--size-only".

Yes. My past experience has shown me that some ftp client/server
combinations corrupt resumed downloads, that's why I don't use
--size-only. To think again about it, a MD5SUMS.gz file covering
every file in the tree would help checking against such problems.
After that, rsync could be run with --size-only. This way the server
would not suffer under additional load and the client could still
verify the correctness of all files.

My script has a few features which are only desirable if you do
not convert from ftp. Thinking again, I'll add support for a
MD5SUMS.gz file if there is any. That would combine the best
of both worlds and keep the load on the server low.

Regards,
Carl-Daniel

---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to