When backing up data and getting very slow transfer rate between server and client despite the fast network connection its important to look at the server and client network stats:
Server:
Ifconfig (errors:6 dropped:12 overruns:6) shows network congestion):
[root@bugs ~]# ifconfig -a eth0 eth0 Link encap:Ethernet HWaddr 00:30:48:76:B8:EC inet addr:192.168.10.10 Bcast:192.168.10.255 Mask:255.255.255.0 inet6 addr: fe80::230:48ff:fe76:b8ec/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:44088695 errors:6 dropped:12 overruns:6 frame:0 TX packets:27228292 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2059358934 (1.9 GiB) TX bytes:2541857653 (2.3 GiB) Base address:0xa800 Memory:f2000000-f2020000
Iptraf (amanda server is limiting how much data can be trasfered to it from the client):
eth0 3416410 3416410 0 0 59822.20 kbits/secc
Client:
Ifconfig (errors:10 dropped:0 overruns:10 frame:10) shows network congestion:
bash-3.00# ifconfig -a eth0 eth0 Link encap:Ethernet HWaddr 00:15:F2:92:F8:54 inet addr:192.168.10.111 Bcast:192.168.10.255 Mask:255.255.255.0 inet6 addr: fe80::215:f2ff:fe92:f854/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:25108061 errors:10 dropped:0 overruns:10 frame:10 TX packets:31648975 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1278188716 (1.1 GiB) TX bytes:1865504070 (1.7 GiB) Interrupt:11 Memory:feafc000-0
bash-3.00#
Iptraf (amanda client is sending data faster then server allows to recieve):
eth0 4529880 4529880 0 0 88353.20 kbits/secc
The solution to this problem is to increase the netusage parameter in advanced.conf depending on you network bandwith (its recomended to increase this parameter until the network congestion is resolved):
netusage 100000 Kbs # maximum net bandwidth for Amanda, in KB per sec