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 -- To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html