I encountered the exact same issue with loss of network upgrading Ubuntu 12.04LTS 32-bit to 14.04LTS 32-bit on a Hyper-V VM (Windows 2008R2). I went through the same steps to do a fresh install of 14.04LTS 32-bit and had the same result. Also found Ubuntu 14.04LTS 64-bit worked well and did not experience this issue.
After much testing, I found that if I dropped the RAM of the Ubuntu 14.04LTS VM to 4014MB on 2008R2 Hyper-V (4026MB on Hyper-V 2012R2), the network adapter will show up and network connectivity will resume (Will have internal system errors however). I then dropped to 2048MB and Ubuntu is stable and network is connected. My Ubuntu 12.04LTS 32-bit VMs run 4GB wonderfully and never experienced issues with memory/networking. Also tested on different hosts and found this network issue is the same on Hyper-V versions 2008R2, 2012 and 2012R2 when memory is pushed to 4GB for the VMs. I tested Ubuntu 14.04LTS 32-bit on a physical machine with 4GB of RAM and system runs great, no network issues. The download of 14.04LTS 32-bit does display "for machines running 2GB or less". How much memory are you giving affected VMs? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1338185 Title: networking fails in 32-bit 14.04 using HyperV on Win2012R2 Status in “linux” package in Ubuntu: Confirmed Bug description: I was running Ubuntu 13.10 32-bit as a VM on a Windows Server 2012 R2 machine with Hyper-V. In 32-bit 13.10, networking worked properly at all times, from the first installation to normal usage. I ran the upgrade to 32-bit Ubuntu 14.04 and discovered that networking is no longer working. To eliminate the possibility that there was a botched upgrade, I tried a fresh install in another VM. I performed a fresh install of 32-bit Ubuntu 14.04 in Hyper-V from ubuntu-14.04-desktop-i386.iso, and I noticed that the network was not connecting during the first part of the installation before any files are copied to the disk. After the installation completed, there was no eth0 device present. By comparison, I performed a fresh install of 64-bit Ubuntu 14.04 in Hyper-V from the ubuntu-14.04-desktop-amd64.iso, and networking worked properly at all times from the start of installation. To summarize, networking is failing in 32-bit Ubuntu 14.04 under Hyper-V in Windows Server 2012 R2. Networking is working properly in 32-bit Ubuntu 13.10 on the same machine. Networking is working properly in 64-bit Ubuntu 14.04 on the same machine. Any suggestions on getting 32-bit Ubuntu 14.04 to work in my Hyper-V VM ? Thanks. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1338185/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
