I was wondering why scp didn't have a restart-in-the-middle option when transferring a large file. Isn't that something that is supported by the underlying ssh protocol? Is there some other program that can give me this functionality ?
Hi, On Sun, Feb 26, 2012 at 10:02:59AM -0500, Mark Anderson wrote:> I was wondering why scp didn't have a restart-in-the-middle > option when transferring a large file. Isn't that something > that is supported by the underlying ssh protocol? Is there > some other program that can give me this functionality ?rsync (-over-ssh). gert -- USENET is *not* the non-clickable part of WWW! //www.muc.de/~gert/ Gert Doering - Munich, Germany gert at greenie.muc.de fax: +49-89-35655025 gert at net.informatik.tu-muenchen.de
On Feb 26, 2012, at 9:02 AM, Mark Anderson wrote:> I was wondering why scp didn't have a restart-in-the-middle > option when transferring a large file. Isn't that something > that is supported by the underlying ssh protocol? Is there > some other program that can give me this functionality ?Scp came from rcp.. Which is a stupid simple(ish) protocol more like doing: tar -cvf | ssh tar -xvf. So it really has nothing to do with the ssh protocol itself as it just needs a streaming socket to throw data at. I suspect you're thinking sftp service, and that could be easily extended to support it. I did a cheap proof of concept that required adding an sha1 hash request extension to the server so I could determine where I needed to pick up in the transfer. It really was an attempt to implement a simplified rsync over sftp. However, that code is long since dead and burned. - Ben
On Sun, Feb 26, 2012 at 1:02 PM, Gert Doering <gert at greenie.muc.de> wrote:> Hi, > > On Sun, Feb 26, 2012 at 12:15:06PM -0500, Mark Anderson wrote: > > I could use rsync but only if that server was running > > on the other end, which is not as likely as sshd. > > Use rsync-over-ssh, not rsync-to-rsyncd, then :-) > > (Of course that requires rsync to be installed on the target machine, > which might not be the case, so I do see your point).rsync is a pretty common system utility. It actually takes *work* to leave it out of most common UNIX or Linux deployments, and it is very easy to test. If the server is one of the commercial SFTP/FTP servers, which are typically Windows based, it may not be available.