I have installed CentOS 6.0 on Hyper-V Server 2008 R2 SP1. VM has only synthetic network adapter enabled. Installation was successfull (without any network), then I installed Linux Integration Services 3.1 from ISO, everything OK too. Now all Hyper-V modules are installed (including hv_netvsc), but there is no network adapter detected.
Running dmesg | grep eth returns message *"Dropping NETIF_F_SG since no checksum feature."* Reserching on internet shows that checksum seems to be some critical feature without which CentOS cannot use the network adapter and which is apparently not implemented by Microsoft's LIS3.1 module.
Is there anything I can do to use synthetic network adapter in CentOS? Or have I done something wrong and it should work as it is? Does synthetic adapter capabilities depend on hardware ethernet card used in the host machine? CentOS kernel version seems to be 2.6.32-71.el6.x86_64, hypervisor is R2 SP1 with all updates installed.
Second question in case the answer for the first is "no, it won't work": Is there a large performance penalty in using emulated (legacy) network driver? Is it something that should be avoided in production environment?