Slow SolusVM Xen Dom0 Network Speed Fixes

If you use Solusvm and Xen on a Centos installation, you may not even notice that by default the “peth0” which is the physical ethernet cable can actually default to Half Duplex, but it’s relatively easy to fix with just a few command.

Centos Commands Bash Commands (run them on Dom0):

#yum install ethtool
#yum install net-tools
#ethtool peth0

The physical port is peth0, not eth0, as such you can only alter the settings on peth0. As you can see from teh box I issued the command on:-

ethtool peth0
Settings for peth0:
Supported ports: [ TP ]
Supported link modes:   10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes:  10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Half
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Link detected: yes

More often than not, if the switch is set to 100Mb, and you have auto on, it will go to half duplex as you can see above, so my suggestion is to set auto negotiation to off, and set the speed you expect from the switch, most hosts have gigabit capable switches.

#ethtool -s peth0 autoneg off
#ethtool -s eth0 duplex full

Job Done. Tested in FTP, suddenly, download rates were much quicker.