I mean this response..... Is it true? Can somebody please shed some light on it...............
Andrew Liles wrote: > I assume > - the remote server is Win2K > - the remote server does not have an rsync daemon > - the remote server is accessed using Samba > > The problem, I reckon, is that your entire set of files is being dragged > across the network to the local machine during the "building file list" > before it properly gets into copying files. > > My simple understanding of what rsync does is this: > Frist: Rsync works out what to send by firstly determining which files > exist on the source (this is a quick "ls" type operation). > > Second: assume a file has an identical file size then rsync must examine > the file to see if it is the same. It does, in essence, by doing a checksum > on the file; I am not sure quite how rsync works, but let's assume it > divides the file into blocks and does a checksum on the first block of > bytes and compares that to the local copy's first block checksum. How can > it do that on the remote Win2K? If you machine has no rsync daemon then > your LOCAL machine needs to calculate the checksum for the REMOTE > file. The checksum is small to transmit over the network, but if the block > is, say 100k, we incur a 100k(+a little bit) network transmission. If the > file is actually identical then WHOLE file has to be transmitted before it > knows that that file does not need to be transferred! > > So why use rsync if it is this "bad"? Well much of the time (a) the remote > runs an rsync daemon so the client can ask the remote to calculate the > checksum, (b) the local can invoke on the remote a shell in which it can > invoke rsync. In the case of Win2K and a Samba share you don't have this > possibility. > > How should you solve it? One way is to use "Cygwin" (www.cygwin.com) which > allows you to run Unix commands (including rysnc) on a Windows platform. I > use rsync CLIENT on a Win2K box fine. What I have not tried is running the > daemon on the Win2K box. Perhaps someone else can confirm this works ok. > > > > At 18:43 16/02/2004, Max Kipness wrote: > >Hello, > > > > > > > >I'm having an issue with one particular server and am hoping someone > >here has dealt with this. > > > > > > > >I'm not sure whether this is a strictly samba issue or relates to the > >way rsync walks the file list. > > > > > > > >Basically after mounting a Windows 2000 file system using and then > >rsyncing the contents of this mount, it seems to take 5 - 8 hours to > >complete. I've checked on the log periodically and determined that it's > >the 'building of the file list' that is taking 95% of the time. We are > >only talking about 140,000 files. I do many samba shares and not of them > >have this issue. When doing a manual 'ls' command in various directories > >on the mount, I encounter no slowness or anything out of the ordinary. > >The samba log doesn't give much of a clue either. > > > > > > > >Has anybody come across this? Or does anybody have any ideas of how to > >troubleshoot? > > > > > > > >Oh, and I'm using Rsync 2.6 > > > > > > > >Thanks, > > > >Max > > > >-- > >To unsubscribe or change options: > >http://lists.samba.org/mailman/listinfo/rsync > >Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html > > -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
