Problem rsyncing 450GB file to my NAS: 'connection unexpectedly closed'

rsyncml.frucade at rsyncml.frucade at
Sat Oct 13 06:03:06 MDT 2012

I can't believe it -- but I DO fiddle around with _wireshark_ to get my 
_backup_ done. Strange age of the 21th century.

Ok - here is what I was able to observe: At first everything seems to be 
fine. After handshake the rsyncd is continuously sending every 1.7s 
packets to the client which the client immediately and silently ACKs.

This goes until some random point in time, where the rsyncd sends within 
the same ms first a regular packet, then a new packet with the timeout 
message and hangsup the connection. Duh!

Even with -vvvvv the logs do not really provide more helpful pointers. A 
quick google search revealed, that really many others share the same 
issue with huge files, though w/o a solution.

The directory contains only 5 files and I was able to obvserve a 
continuous stream of packets, so probably its not about IO operations. 
Maybe some kernel/socket/network stack issue?

I assume that at this point everybody, else is on this list is just as 
puzzled and clueless as I am now?!

- Ben

Am 12.10.2012 22:57, schrieb Justin T Pryzby - justinp at
> You can tcpdump it to see which side is closing the connection.  My
> understanding is that "the network" isn't timing out, but one end of
> the rsync, due to the other end doing slow things at various points in
> the connection.  In the immediate case, one side is probably timing
> out while the other side is still building hashes of the 450G file.
> In other cases, it may be due to scanning a large directory or (pre
> 3.0 or with --no-inc-recur, a large file list across many directories.
> Justin

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