Backup performance and NIC cards

If backup or restore jobs are running slowly, verify that the network interface cards (NIC) are set to full duplex. Half duplex often causes poor performance. For assistance on how to view and reset duplex mode for a particular host or device, consult the documentation that the manufacturer provides, or try the following.

1 Log in to the host that contains the network interface card(s).

2 Enter the following command to view the current duplex setting.

ifconfig -a On some operating systems, this command is ipconfig. Example output from a NAS filer:
e0: flags=1948043 mtu
1500
inet 10.80.90.91 netmask 0xfffff800 broadcast 10.80.95.255
ether 00:a0:98:01:3c:61 (100tx-fd-up) flowcontrol full
e9a: flags=108042 mtu 1500
ether 00:07:e9:3e:ca:b4 (auto-unknown-cfg_down) flowcontrol full
e9b: flags=108042 mtu 1500
ether 00:07:e9:3e:ca:b5 (auto-unknown-cfg_down) flowcontrol full
In this example, the network interface that shows “100tx-fd-up” is running in full duplex. Only interface e0, the first in the list, is at full duplex.

Note: A setting of “auto” is not recommended, because devices can auto negotiate to half duplex.

3 The duplex mode can be reset by using the ifconfig (or ipconfig) command. For example:
ifconfig e0 mediatype 100tx-fd

4 For most hosts, you can set full-duplex mode permanently, such as in the host’s /etc/rc files. Refer to the host’s documentation for more information.