I have a small system that I have been running Cantos 6.6-32 on, all is (was) well.

But I wanted to update, so I installed 7.0-64. From what I read one cannot upgrade from -32 to -64, and there are no versions of 7.x-32 on the Centos site, so I did a new install.

But now I find several anomalies;

1) no networking. running ifconfig, or "nmcli d" (or nmtui) do not show any ethernet adapter (only lo). (It has one, and it was running fine). In /etc/sysconfig/network-scripts/ there are no ifcfg-* files. I plugged in a USB WiFi adapter, and it works fine, so I have some connectivity, but not the regular Ethernet connection.

2) The desktop GUI, does not show the toolbar at the top, with access to the various tools and applications, clock, etc. However this does show up on the login screen - (Choose user).

3) The GUI (which I think by default is gnome) has colors wrong, although the "colors" configuration has the correct monitor, and seems to think it knows the right colors profile. One implication of this is that the login screen, the password field and other fields (and buttons?) flash briefly, and then disappear, and one has to login blind; same for any request for authentication using a pop-up password window. (The only way to get to settings, was to right-click on the desktop, and choose change background, then back navigate to the settings panel)

4) I also do not see the CD/DVD driver in /dev/cdrom -

I'd love to get back to my simple working system! Any hints?

As added below, I found that the install loader was using the monitor at correct resolution, but once booted it changed and was using a wrong resolution, which upon changing the display seems OK.

Also I find that I can do a net-install , so it downloads the entire image over the (Eth0) interface, and installs it, but when it boots, it is not recognized; do I need to do some other setup? but it is not even recognized as an available interface, although if/when I plug in the USB WiFi, it is listed as a network interface for setup.

Also; installing Centos 6.7, it does recognize and properly setup the eth0 network interface - which V7 does not.

                description: Ethernet interface
                product: NM10/ICH7 Family LAN Controller
                vendor: Intel Corporation

It seems that this interface NIC card is one that C7 no longer bundles, although C6 did. Argh - will search for a driver.

  • To me that sounds like a botched install. I would try a re-install, because that certainly does not sound like the expected results. Commented Sep 8, 2015 at 4:17
  • I did a re-install, same results. I figured out from appearances (the screen said "Cent", not "Centos") that although the boot/install used the monitor properly, the actual UI was set to the wrong resolution, so I changed it and then the UI is correct. Still it does not recognize the Ethernet interface.
    – guthrie
    Commented Sep 8, 2015 at 21:49

1 Answer 1


Apparently this was just a symptom of issues with the new version - Centos 7. The monitor was detected at the wrong resolution, and the driver for my NIC card has been removed from V7 although it is in V6 and works fine in the install loader. It appears that there is code for adding a driver for this (older) NIC, but it has to be compiled and built, and users report multiple issues with this process. ... going back to Debian. :-)

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