ssh / scp slow on 10GBE

[Stefan Priebe]

Hi,

Am 03.01.2013 20:19, schrieb Iain Morgan:
> I think you have a typo above. You presumably mean 600-700 MB/s in the
> case of OpenSSL using AES-NI, but do you mean MB/s or Mb/s in the scp
> case?
uups i mean MB in both cases.

> How are you measuring the ssh/scp performance? Is this over a LAN or WAN
> connection?
LAN

> On the other hand, if you are getting 76 MB/s, then you may have some
> other bottlenecck to address. You might try doing a dd through ssh to
> factor out scp and disk I/O. For example,
>
> % dd if=/dev/zero bs=1048576 count=4096 | ssh somehost dd of=/dev/null
#~ dd if=/dev/zero bs=1048576 count=4096 | ssh -c aes128-cbc 10.255.0.24 
dd of=/dev/null
4096+0 records in
4096+0 records out
4294967296 bytes (4,3 GB) copied, 19,3355 s, 222 MB/s
8388608+0 records in
8388608+0 records out
4294967296 bytes (4,3 GB) copied, 18,6107 s, 231 MB/s

But:
# iperf -c 10.255.0.24 -t 30 -d
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 10.255.0.24, TCP port 5001
TCP window size:   990 KByte (default)
------------------------------------------------------------
[  4] local 10.255.0.22 port 44006 connected with 10.255.0.24 port 5001
[  5] local 10.255.0.22 port 5001 connected with 10.255.0.24 port 37393
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-30.0 sec  34.6 GBytes  9.90 Gbits/sec
[  5]  0.0-30.0 sec  33.9 GBytes  9.70 Gbits/sec

and
openssl aes-128-cbc speed:

The 'numbers' are in 1000s of bytes per second processed.
type             16 bytes     64 bytes    256 bytes   1024 bytes   8192 
bytes
aes-128-cbc     648664.33k   688924.90k   695855.45k   700784.64k 704027.06k

Greets,
Stefan