rsync hanging with openssh-2.9.9p2 as the transport

[Andrew J. Schorr]

Hi,

This is perhaps a stupid question.  I apologize in advance if it's already
been covered, but I'm stumped...

I'm using rsync to backup some file systems to a remote host.
The transport is openssh-2.9.9p2.

The problem does not occur when the transport is rsh.

I'm invoking rsync as follows:

  rsync -RlHptgoD --numeric-ids -e "ssh" -rzx --stats . remotehost:/nfs/mirror

But it hangs when there are large numbers of files in the "." filesystem.
If I run with -vvv, I see lots of make_file entries as send_file_list
starts sending the list of files to the remote host, but then it freezes
after around 4500 to 6500 make_file messages.

I see the same problem with versions 2.4.6, 2.5.5, and 2.5.6pre1.
And I see it on linux 2.4.18 (red hat 8.0) and solaris 8/x86.

I can get it to work by breaking it up into chunks of 1000 files or
so.  It might work with more, I haven't tested exhaustively.

I have tried using the --blocking-io and --no-blocking-io options, but
neither one solves the problem.

I could provide more info about where it hangs, but I thought somebody
might know the answer, since this is clearly related to the
interaction with openssh (since there's no problem with rsh).

Is there a trick to make rsync work nicely with openssh?  I searched the
archives and haven't found anything...  Does upgrading to openssh 3 solve
the problem?

Thanks,
Andy