Hi Pavel,

  thank you very much for the info. That is very useful for me. However 
I think that there is a version-based misunderstanding mixed to some 
bugs in the most recent ones. It looks like that in the old prod version 
there was no xrootd.prep directive, that's the point of confusion.

  In the meantime I reverted back to my local machine (and a simpler 
config file) to do this kind of tests. I believe I found a weirdness in 
the config error as reported. Here it is:

- no xrootd.prep directive ---> prepare is off (ok!)
- xrootd.prep logdir /tmp/prestage_log ---> the server refuses to start

Step 1:
  Imho there is some bug in the config parsing, because having a look at 
the code and at the strace log, we see that xrootd creates the dir 
/tmp/prestage_log, and then looks for /tmp/prestage_log/anon, which was 
not created. Hence it exits with an error. This is very confusing. Andy, 
what do you think?

070830 14:22:40 001 XrootdConfig: Unable to process logdir 
/tmp/prestage_log; no such file or directory
=====> xrootd.prep logdir /tmp/prestage_log

Step 2:
  I create the dir /tmp/prestage_log/anon, and now the server starts, 
apparently fine.

Step 3:
  I connect with the xrd app and request a prepare. The server answers 
ok, and nothing happens... This is the request sent by the client:

================= DUMPING CLIENT REQUEST HEADER =================
                 ClientHeader.streamid = 0x01 0x00
                ClientHeader.requestid = kXR_prepare (3021)
          ClientHeader.prepare.options = 0x08
             ClientHeader.prepare.prty = 0x00
         ClientHeader.prepare.reserved = 0 repeated 14 times
              ClientHeader.header.dlen = 5
=================== END CLIENT HEADER DUMPING ===================

  And this is what the server says in the log (olbd says nothing):

070830 14:38:29 2295 furano.2318:[log in to unmask] 
XrootdProtocol: 0100 req=3021 dlen=5
070830 14:38:29 2295 furano.2318:[log in to unmask] 
XrootdResponse: 0100 sending 24 data bytes; status=0
070830 14:38:32 2295 furano.2318:[log in to unmask] 
XrootdProtocol: 0100 request timeout; read 0 of 24 bytes
070830 14:38:32 2295 furano.2318:[log in to unmask] XrdPoll: 
sending poller 0 enable for link 15
070830 14:38:32 2295 XrdPoll: Poller 0 enabled fd 15 entry 1 now at 2
070830 14:38:54 2295 XrdSched: running 
furano.2318:[log in to unmask] inq=0
070830 14:38:54 2295 XrootdXeq: furano.2318:[log in to unmask] 
disc 0:00:44

Step 4:
  If I lurk inside /tmp/prestage_log/anon I see that the server created 
some files with complicated names, containing the filename I requested 
to stage. Now I am sure I am missing something, because still nothing 
happens. Instead the normal staging works. What's missing here? Andy, 
Pavel, do you have any suggestion? I attach my config file to the email.

Thank you!