On Apr 15, 11:25 pm, Peer-Joachim Koch <pk...@bgc-jena.mpg.de> wrote:

> I'm currently trying to reduce our backup time. We have to transfer
> ~250GB/day (50GB-2000GB).
> We tried to connect one of the file server using bonding and 2 unused
> network interfaces to improve the performance, but we are only seeing
> a small improvement (5-10%; averg. is currently 60MB/s).

Most bonding implementations assign a connection to a link, so a
single connection will not run any faster.

> So I started to play a little bit on our cluster, where we have a couple
> of nodes with bonding interfaces. Using netcat I can transfer a file
> of 670MB within 5.9 sek, but this is only the theor. value for
> 1 GBit.

Yep, that's what I would expect.

> Using scp I can only see ~45MB/s. (it's a 8 core node, so it's fast
> enough ...).

Since SCP is not multi-threaded, the transfer speed is limited by how
fast one core can do encryption. Last I checked, there was a huge
speed difference between various ciphers, so you might try a few to
see which is fastest.

DS