Slow scp/graphics connection.

["Rosin, Angela" <lister@liverpool.ac.uk>]

Apologies if you are seeing this twice: for some reason my account started bouncing the group yesterday and I had to resub.

I have a suite of 11 computers running debian etch (2.6.18-3-686 server, 2.6.18-4-686 on the nodes).  We use Condor and nfs to manage user accounts from a central server.  Recently I've noticed an intermittent problem with graphical login: it takes a long time to log in and applications are slow.  This is odd as it's only the home directory that is exported - everything else is managed on the node.  I've also had a problem today with scp.  A 12MB file takes 2 minutes and spents a lot of time stalled.  The network team have checked that it isn't a problem their end so I'm assuming it's a problem with this machine, either with the network card or transfer protocal compatibility issues.  I've had a mooch round the web but networking is so far out of my comfort zone I'm practically perching on broken glass and my normal response would be to restart the server.  As I've users running long jobs I'd appreciate some pointers to fixing it without resorting to a restart.

What I have done so far:  I've checked that the nfsd daemons are running.  I've restarted portmap.  I've run top to see if there is a rogue process running, ditto ps.  The machines use KDE as default and we are on 3.5.  Does anyone have an idea of where I should be looking to improve performance/iron out a problem.  I've attached ping output as well as ifconfig for the server.

Thanks in advance for any help you can give.

Ang


Outward ping (server to node) is
7 packets transmitted, 7 received, 0% packet loss, time 6009ms rtt min/avg/max/mdev = 8.020/35.689/41.240/11.334 ms

Inward ping (node to server) is
8 packets transmitted, 8 received, 0% packet loss, time 7005ms rtt min/avg/max/mdev = 27.802/32.252/37.664/3.603 ms

Output of ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:13:72:75:15:E2
          inet addr:138.253.199.46  Bcast:138.253.199.255  Mask:255.255.252.0
          inet6 addr: fe80::213:72ff:fe75:15e2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:588806152 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3795714138 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:3204959342 (2.9 GiB)  TX bytes:2429011615 (2.2 GiB)
          Base address:0xdcc0 Memory:dfee0000-dff00000

eth1      Link encap:UNSPEC  HWaddr 80-75-00-13-15-E2-72-00-00-00-00-00-00-00-00-00
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:767193 errors:0 dropped:0 overruns:0 frame:0
          TX packets:767193 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1554133767 (1.4 GiB)  TX bytes:1554133767 (1.4 GiB)

sit0      Link encap:IPv6-in-IPv4
          NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)