I am having trouble running rsync over a mapped drive. Basically it only copies whole files. I use the -rvcS switches. Any suggestions? TIA _____________________________ Stephen Zemlicka Integrated Computer Technologies PH. 608-558-5926 E-Mail <mailto:stevezemlicka@gmail.com> stevezemlicka@gmail.com -------------- next part -------------- HTML attachment scrubbed and removed
On 9/24/07, Stephen Zemlicka <stevezemlicka@gmail.com> wrote:> I am having trouble running rsync over a mapped drive. Basically it only > copies whole files. I use the ?rvcS switches. Any suggestions?The delta-transfer algorithm reduces only the communication between the sending and receiving rsync processes; each process reads and writes entire files in whatever filesystem it is using (local or networked). If you want to benefit from delta transfers, one of the rsync processes has to actually run on the system hosting the mapped drive. You can accomplish this either by remote shell or by setting up and accessing an rsync daemon on that system. Matt
On Mon 24 Sep 2007, Stephen Zemlicka wrote:> I am having trouble running rsync over a mapped drive. Basically it only > copies whole files. I use the -rvcS switches. Any suggestions?>From the manpage:-W, --whole-file With this option the incremental rsync algorithm is not used and the whole file is sent as-is instead. The transfer may be faster if this option is used when the bandwidth between the source and destination machines is higher than the bandwidth to disk (especially when the "disk" is actually a networked filesystem). This is the default when both the source and des- tination are specified as local paths. This is because there's no advantage to updating only parts instead of the whole file. If rsync finds it needs to update a file, it now only has to read the source, write the destination (via a temp file so that the destination filename either points to the old version or the new version; not an incomplete new version. If you want that, use --inplace). If it did it incrementally, then rsync would need to read the source, read the old destination file, compare, and while writing the new temp file read from either the source or the old destination. This is more IO, and hence less efficient. Rsync's incremental algorithm is for optimizing network traffic at the expense of more local disk IO, in the assumption that the network is slower than local disk IO. If you're doing a local transfer, it optimizes the disk IO... Using a mapped drive appears to be a local disk. If you can transfer directly between the server from which the drive is mapped instead of going through the mapping, then that's preferable (and will decrease network traffic...). Paul Slootman
What exactly is involved in the remote shell? Can this be done on a windows to windows backup? Do you have a link handy otherwise google to the rescue. Thank you very much. _____________________________ Stephen Zemlicka Integrated Computer Technologies PH. 608-558-5926 E-Mail stevezemlicka@gmail.com -----Original Message----- From: hashproduct@gmail.com [mailto:hashproduct@gmail.com] On Behalf Of Matt McCutchen Sent: Monday, September 24, 2007 12:09 PM To: Stephen Zemlicka Cc: rsync@lists.samba.org Subject: Re: Mapped Drive On 9/24/07, Stephen Zemlicka <stevezemlicka@gmail.com> wrote:> I am having trouble running rsync over a mapped drive. Basically it only > copies whole files. I use the -rvcS switches. Any suggestions?The delta-transfer algorithm reduces only the communication between the sending and receiving rsync processes; each process reads and writes entire files in whatever filesystem it is using (local or networked). If you want to benefit from delta transfers, one of the rsync processes has to actually run on the system hosting the mapped drive. You can accomplish this either by remote shell or by setting up and accessing an rsync daemon on that system. Matt
On 9/24/07, Stephen Zemlicka <stevezemlicka@gmail.com> wrote:> What exactly is involved in the remote shell? Can this be done on a windows > to windows backup? Do you have a link handy otherwise google to the rescue. > Thank you very much.You set up an ssh server on the machine with the mapped drive, install an ssh client on the machine running rsync, and direct rsync to the mapped drive using a path of the form host:/cygdrive/C/path/to/mapped/drive/ (note the *single* colon). cwRsync ( http://itefix.no/cwrsync/ ) is a nice packaging containing rsync, an ssh client and server, and some glue to get the ssh server running in Windows; I recommend it. Note: you might run into the infamous remote-rsync-under-Cygwin hang bug, which is being tracked here: https://bugzilla.samba.org/show_bug.cgi?id=2208 Matt
for now there is no caching - anyway - how should checksums be cached? if mtime/size is no reliable method for detecting file changes and checksum is the only method - to detect if you need to update the cache you need to ... checksum .... and thus a checksum cache is quite nonsense, imho.> I suppose it could be cached at either storage location.if you use rsync on a mapped drive, you have no "local" and "remote" storage location from an rsync`s point of view, because rsync isn`t being executed on the remote node. so if rsync calculates a checksum it`s always transferring the whole file via mapped drive. regards roland> -----Urspr?ngliche Nachricht----- > Von: "Stephen Zemlicka" <stevezemlicka@gmail.com> > Gesendet: 30.09.07 07:30:04 > An: "'Matt McCutchen'" <hashproduct+rsync@gmail.com> > CC: rsync@lists.samba.org > Betreff: RE: Mapped Drive> > The problem is some files don't change in size. So I was hoping that the > checksums could be cached. Perhaps I'm mistaken but I thought the checksum > determined what actual blocks were transferred. I suppose it could be > cached at either storage location. > > _____________________________ > Stephen Zemlicka > Integrated Computer Technologies > PH. 608-558-5926 > E-Mail stevezemlicka@gmail.com > > -----Original Message----- > From: hashproduct@gmail.com [mailto:hashproduct@gmail.com] On Behalf Of Matt > McCutchen > Sent: Saturday, September 29, 2007 5:03 PM > To: Stephen Zemlicka > Cc: rsync@lists.samba.org > Subject: Re: Mapped Drive > > On 9/28/07, Stephen Zemlicka <stevezemlicka@gmail.com> wrote: > > Is there a way to have rsync cache the checksums for something like this > and > > would that help? > > I'm not sure exactly what you mean. You said you were using the -c > (--checksum) option, which makes rsync decide whether to update each > destination file by reading the file in full and comparing its MD4/MD5 > checksum with that of the source file. Do you mean you want rsync to > cache the checksums of the destination files? On which machine would > the cache be? > > Anyway, if the issue is that you don't want rsync spending the > bandwidth to read the destination files for the --checksum check, just > remove -c and rsync will use the default size-and-mtime quick check. > > Matt > > -- > To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync > Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html >_________________________________________________________________________ In 5 Schritten zur eigenen Homepage. Jetzt Domain sichern und gestalten! Nur 3,99 EUR/Monat! http://www.maildomain.web.de/?mc=021114