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