#StackBounty: #centos #networking #rhel #kvm RHCE Study Lab: KVM networking and ping issues

Bounty: 150

I’m trying to setup an RHCE study lab per Michael Jang’s RHCSA/RHCE setup guide. I’ve followed the guide in the book to the dot, though in my opinion a lot of information is missing (step by step would have been nice for such a book).

TL;DR – I cannot get VMs to talk to each other in the same subnet in my KVM setup. My study guide says to use Forward NAT with the virbr# devices…but it is not working.

The main issue I am having is that my VMs cannot ping anything on the networks: “destination host unreachable”. server1 cannot ping its default gateway, the host computer, or even tester1, which is on the same subnet. The same is true for trying to reach outsider1, which is a different subnet on the same KVM host PC. The same behavior is present on the VMs tester1 and outsider1 too.

For the setup, I have a host computer on a private network (192.168.5.0/24), and per the book I created two KVM virtual networks and three VMs. Below is a summary of the configuration for each VM.

server1.example.com

  • attached to virtual network ‘example.com’: NAT
  • device model: virtio
  • vNIC MAC 52:54:00:86:51:d2
  • static IP: 192.168.122.50/24, gw=192.168.122.1

tester1.example.com

  • attached to virtual network ‘example.com’: NAT
  • device model: virtio
  • vNIC MAC 52:54:00:89:20:c7
  • static IP: 192.168.122.150/24, gw=192.168.122.1

outsider1.example.org

  • attached to virtual network ‘example.org’: NAT
  • device model: virtio
  • vNIC MAC 52:54:00:03:c3:0a
  • static IP: 192.168.100.100/24, gw=192.168.100.1

I followed the directions to create two virtual networks, and the setup as seen from the virtualization host PC is as follows:

# virsh list
 Id    Name                           State
----------------------------------------------------
 1     outsider1                      running
 2     tester1                        running
 4     server1                        running

# virsh net-list
 Name                 State      Autostart     Persistent
----------------------------------------------------------
 example.com          active     yes           yes
 example.org          active     yes           yes

# virsh net-info example.com
Name:           example.com
UUID:           6d2a6e12-2d72-4720-9427-630a608bae6f
Active:         yes
Persistent:     yes
Autostart:      yes
Bridge:         virbr0

# virsh net-info example.org
Name:           example.org
UUID:           3d564af8-4d3e-484b-846e-7ad76bd4be4a
Active:         yes
Persistent:     yes
Autostart:      yes
Bridge:         virbr1

# virsh net-dumpxml example.com
<network>
  <name>example.com</name>
  <uuid>6d2a6e12-2d72-4720-9427-630a608bae6f</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:7f:b9:50'/>
  <domain name='example.com'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.151' end='192.168.122.254'/>
    </dhcp>
  </ip>
  <ip family='ipv6' address='fd00:a81d:a6d7:55::1' prefix='64'>
    <dhcp>
      <range start='fd00:a81d:a6d7:55::100' end='fd00:a81d:a6d7:55::1ff'/>
    </dhcp>
  </ip>
</network>

# virsh net-dumpxml example.org
<network>
  <name>example.org</name>
  <uuid>3d564af8-4d3e-484b-846e-7ad76bd4be4a</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr1' stp='on' delay='0'/>
  <mac address='52:54:00:49:c7:35'/>
  <domain name='example.org'/>
  <ip address='192.168.100.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.100.128' end='192.168.100.254'/>
    </dhcp>
  </ip>
  <ip family='ipv6' address='fd00:e81d:a6d7:56::1' prefix='64'>
    <dhcp>
      <range start='fd00:e81d:a6d7:56::100' end='fd00:e81d:a6d7:56::1ff'/>
    </dhcp>
  </ip>
</network>

# brctl show
bridge name bridge id       STP enabled interfaces
docker0     8000.02428a3f4914   no      
virbr0      8000.5254007fb950   yes     virbr0-nic
virbr1      8000.52540049c735   yes     virbr1-nic

# ip route show
default via 192.168.5.1 dev enp0s31f6 proto dhcp metric 100 
192.168.5.0/24 dev enp0s31f6 proto kernel scope link src 192.168.5.45 metric 100 
192.168.100.0/24 dev virbr1 proto kernel scope link src 192.168.100.1 
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 

# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp0s31f6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 2c:4d:54:d2:c5:89 brd ff:ff:ff:ff:ff:ff
    inet 192.168.5.45/24 brd 192.168.5.255 scope global noprefixroute dynamic enp0s31f6
       valid_lft 71762sec preferred_lft 71762sec
    inet6 fe80::7abc:be60:6633:d94/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:8a:3f:49:14 brd ff:ff:ff:ff:ff:ff
10: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether fe:54:00:03:c3:0a brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:fe03:c30a/64 scope link 
       valid_lft forever preferred_lft forever
11: vnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether fe:54:00:89:20:c7 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:fe89:20c7/64 scope link 
       valid_lft forever preferred_lft forever
13: vnet2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether fe:54:00:86:51:d2 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:fe86:51d2/64 scope link 
       valid_lft forever preferred_lft forever
14: virbr1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:49:c7:35 brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.1/24 brd 192.168.100.255 scope global virbr1
       valid_lft forever preferred_lft forever
    inet6 fd00:e81d:a6d7:56::1/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe49:c735/64 scope link 
       valid_lft forever preferred_lft forever
15: virbr1-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr1 state DOWN group default qlen 1000
    link/ether 52:54:00:49:c7:35 brd ff:ff:ff:ff:ff:ff
16: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:7f:b9:50 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
    inet6 fd00:a81d:a6d7:55::1/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe7f:b950/64 scope link 
       valid_lft forever preferred_lft forever
17: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:7f:b9:50 brd ff:ff:ff:ff:ff:ff

I have tried restart NetworkManager on all of the VMs, as well as restarting the VMs too, but none of the VMs can talk to any other device. Clearly I am missing a step in order to get these devices to talk to each other…

Server1 is configured as follows:

[root@server1 ~]# ip route show
default via 192.168.122.1 dev eth0  proto static  metric 100 
192.168.122.0/24 dev eth0  proto kernel  scope link  src 192.168.122.50  metric 100 
[root@server1 ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
    link/ether 52:54:00:86:51:d2 brd ff:ff:ff:ff:ff:ff
[root@server1 ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:86:51:d2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.50/24 brd 192.168.122.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe86:51d2/64 scope link 
       valid_lft forever preferred_lft forever

Tester1 is configured as follows:

[root@tester1 ~]# ip route show
default via 192.168.122.1 dev eth0  proto static  metric 100 
192.168.122.0/24 dev eth0  proto kernel  scope link  src 192.168.122.150  metric 100 
[root@tester1 ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
    link/ether 52:54:00:89:20:c7 brd ff:ff:ff:ff:ff:ff
[root@tester1 ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:89:20:c7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.150/24 brd 192.168.122.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe89:20c7/64 scope link 
       valid_lft forever preferred_lft forever

And outsider1 is configured as follows:

[root@outsider1 ~]# ip route show
default via 192.168.100.1 dev eth0  proto static  metric 100 
192.168.100.0/24 dev eth0  proto kernel  scope link  src 192.168.100.100  metric 100 
[root@outsider1 ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
    link/ether 52:54:00:03:c3:0a brd ff:ff:ff:ff:ff:ff
[root@outsider1 ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:03:c3:0a brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.100/24 brd 192.168.100.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe03:c30a/64 scope link 
       valid_lft forever preferred_lft forever

I’m pretty sure I will need to create static routes on the hosts to get traffic going from outsider1 to tester1/server1 and vice versa. But what really has me stuck is that I cannot even get tester1 and server1 to talk to each other, or even talk to the default gateway virbr0.

Any ideas?


Get this bounty!!!

#StackBounty: #centos #openvpn #startup #upstart #transmission How to set up OpenVPN and Transmission to start at boot on CentOS 6?

Bounty: 150

I’m trying to set up Transmission with OpenVPN on a headless server running a minimal install of CentOS 6.10, and ideally these would start when I boot the system.

I’m able to get everything to run by following the steps here and here — but that only works when running the script (vpn.sh, as per the two tutorials) manually. That script looks like this:

#!/bin/sh

sudo openvpn --cd /etc/openvpn --config /etc/openvpn/conf.ovpn --script-security 2 --up /etc/openvpn/up.sh

I might add that in addition to OpenVPN and Transmission, I also have this Telegram bot that should start after all else is up, so my up.sh file also has one more line at the end and looks like this:

#!/bin/sh

/etc/init.d/transmission-daemon stop
/bin/sed s/IP_ADDRESS/$4/ /var/lib/transmission/.config/transmission/settings_template.json > /var/lib/transmission/.config/transmission/settings.json
/etc/init.d/transmission-daemon start
/etc/init.d/transmission-telegram start

Ideally, I’d be able to do something a bit more like what this post outlines, though I’m not particularly picky about whether all the traffic goes through the VPN or if only the torrent traffic does:

  1. Start OpenVPN at boot (after networking is up);
  2. If the VPN connection goes through, configure Transmission to run through it;
  3. If that goes through, run Transmission (and the Telegram bot);
  4. If at any time the VPN goes down, also bring Transmission (and the Telegram bot) down gracefully.

I tried following the steps outlined in that post, and for some reason I just can’t get the event transmission-vpn-up to happen — triggered by the route-up.sh script in the tutorial — and always get initctl: Event failed. I’m not able to emit the event either by following the steps in the post, nor by passing the contents of the script manually to the command line. route-up.sh, as per the post on Ask Ubuntu, looks like this:

#! /bin/bash

/sbin/initctl emit transmission-vpn-up VPN_GATEWAY=$route_vpn_gateway LOCAL_IP=$ifconfig_local

If I pass the contents of down.sh to the command line, though, I get no such error:

/sbin/initctl emit transmission-vpn-down

Tried passing both with sudo and without it.

Is there a simple way for me to set this whole thing up? Am I missing something in particular with emitting the transmission-vpn-up specified in the other tutorial on AU, y’know, given that it’s a tutorial for Ubuntu and not CentOS?

Alternatively, would it be easier to just make vpn.sh (the first chunk of code in this post) run at boot? It would be as neat or graceful if the VPN goes down, but it’d do the trick.


Get this bounty!!!

#StackBounty: #centos #gnome #mate-desktop How do we enable quick launcher and Min,max button in MATE (CentOS)?

Bounty: 50

I have installed MATE desktop environment in my CentOS (version 7.5 x64). But there is no quick launcher ‘applications’ button and also my VS code installation doesn’t have min,max,close buttons.

I have used below command to install MATE desktop.

yum -y groupinstall "MATE Desktop"

What is wrong? enter image description here

In Gnome 3 desktop, ‘application’ button shown as below. how to enable ‘application’ button in MATE?

enter image description here


Get this bounty!!!

#StackBounty: #centos #redhat #mount #loop-device loop device does not auto detach on umount

Bounty: 50

I have a backup script in which I umount a squashfs file, I do backup then mount it back again. A simplified version of the script is:

umount /home/backup/auto/mnt/os
mksquashfs /src-dir /home/backup/auto/os.sqfs.img
mount -t squashfs -o loop /home/backup/auto/os.sqfs.img /home/backup/auto/mnt/os

The idea is to have access at all times to backedup data.

And this worked for long time. However I got an error of not having enough loopback devices and I saw that umount does not detach loop devices mounted with mount anymore.

Lately I had two major changes:

  1. I updated the kernel to 2.6.32-754.11.1.el6.i686
  2. I moved the OS to an SSD.

I just noticed that there is new kernel update 2.6.32-754.12.1.el6, so I updated, but it did not fix the problem.

OS: CentOS 6.10


Get this bounty!!!

#StackBounty: #centos #x11 #gnome #nvidia #nouveau GNOME issues on a laptop with Nvidia GEForce graphic card

Bounty: 50

I have installed CentOS 7 on dual boot on an 10ish-year-old Toshiba Qosmio laptop which came with Windows 7.

I did the minimal install, yum update, then installed the “GNOME desktop” group package and started GNOME via startx. It worked for some seconds, then it froze when I selected the options for power management.

After reboot, it asks the LUKS password, it shows the GNOME prompt to select the user, then the screen stays black while the CPU fan turns like mad. After a few minutes the CapsLock key light starts blinking.

I’ve tried to boot at GRUB with a previous kernel version but it does the same, except for the CapsLock key light.

The laptop has a Nvidia GEForce GTX 560m, might the cause be a wrong graphic driver?


EDIT 22/3: I removed the nouveau driver and installed the appropriate Nvidia graphic driver as described here. System is set to boot to multi-user.target.

Now when I run startx the screen goes black for a split second and then outputs the following error:

xauth:  file /home/dr/.serverauth.6309 does not exist


X.Org X Server 1.20.1
X Protocol Version 11, Revision 0
Build Operating System:  3.10.0-957.1.3.el7.x86_64
Current Operating System: Linux hackbox 3.10.0-957.10.1.el7.x86_64 #1 SMP Mon Mar 18 15:06:45 UTC 2019 x86_64
Kernel command line: BOOT_IMAGE=/vmlinuz-3.10.0-957.10.1.el7.x86_64 root=UUID=3a27c3be-ea50-4548-92db-53879292b3aa ro rd.luks.uuid=luks-fac75b1c-2869-4923-8ff1-0e7e7e868dd3 rd.luks.uuid=luks-735bf876-be70-40a4-ac81-f6c6ab46b542 rhgb quiet nouveau.modeset=0
Build Date: 14 March 2019  10:37:36AM
Build ID: xorg-x11-server 1.20.1-5.3.el7_6
Current version of pixman: 0.34.0
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Sat Mar 23 11:40:25 2019
(==) Using config directory: "/etc/X11/xorg.conf.d"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(II) modeset(0): Initializing kms color map for depth 24, 8 bpc.
xinit: connection to X server lost

waiting for X server to shut down (II) Server terminated successfully (0). Closing log file.

Here are the relevant lines from /var/log/Xorg.0.log, reporting only the lines with warnings or errors:

(...)
[   409.722] (II) modeset(0): using drv /dev/dri/card0
[   409.722] (WW) Falling back to old probe method for fbdev
[   409.722] (II) Loading sub module "fbdevhw"
[   409.722] (II) LoadModule: "fbdevhw"
[   409.722] (II) Loading /usr/lib64/xorg/modules/libfbdevhw.so
[   409.723] (II) Module fbdevhw: vendor="X.Org Foundation"
[   409.723]    compiled for 1.20.1, module version = 0.0.2
[   409.723]    ABI class: X.Org Video Driver, version 24.0
[   409.723] (EE) [drm] Failed to open DRM device for (null): -2
[   409.724] (II) modeset(0): Creating default Display subsection in Screen section
        "Default Screen Section" for depth/fbbpp 24/32
[   409.724] (==) modeset(0): Depth 24, (==) framebuffer bpp 32
[   409.724] (==) modeset(0): RGB weight 888
[   409.724] (==) modeset(0): Default visual is TrueColor
[   409.724] (II) Loading sub module "glamoregl"
[   409.724] (II) LoadModule: "glamoregl"
[   409.725] (WW) Warning, couldn't open module glamoregl
[   409.725] (EE) modeset: Failed to load module "glamoregl" (module does not exist, 0)
[   409.725] (EE) modeset(0): Failed to load glamor module.
(...)
[   409.766] (II) Initializing extension GLX
[   409.766] (EE) Failed to initialize GLX extension (Compatible NVIDIA X driver not found)
(...)

and the output of lsmod | grep nvidia :

nvidia_drm             39676  0
nvidia_modeset       1108588  1 nvidia_drm
nvidia              14368631  1 nvidia_modeset
ipmi_msghandler        56032  2 ipmi_devintf,nvidia
drm_kms_helper        179394  3 i915,nouveau,nvidia_drm
drm                   429744  6 ttm,i915,drm_kms_helper,nouveau,nvidia_drm

EDIT 28/3: It seems that glamoregl is part of the ATI driver framework and does not work with Nvidia. So I uninstalled xorg-x11-glamor (and had to reinstall xorg-x11-server which was deleted as a dependency).

The X log reported errors about missing fbdev and vesa drivers, so I installed xorg-x11-drv-fbdev-0.5.0-1.el7.x86_64 and
xorg-x11-drv-vesa.x86_64.

I also installed xorg-x11-drv-nouveau.x86_64 and reenabled it from the kernel options in GRUB.

Now startx correctly starts Gnome but it doesn’t accept any keypress or mouse input. Gnome however is functional, because the clock in the upper right corner works, and I can run commands on this X instance by ssh’ing to the laptop from a different computer and launching GUI programs by specifying the target display, e.g.:

DISPLAY=:3 gedit

which opens the Gedit application on the laptop screen.

Note that the X log doesn’t contain any error, only a warning:

[   197.636] (WW) Falling back to old probe method for fbdev


Get this bounty!!!

#StackBounty: #centos #x11 #gnome #nvidia #nouveau GNOME does not boot on a Toshiba laptop with Nvidia GEForce

Bounty: 50

I have installed CentOS 7 on dual boot on an 10ish-year-old Toshiba Qosmio laptop which came with Windows 7.

I did the minimal install, yum update, then installed the “GNOME desktop” group package and started GNOME via startx. It worked for some seconds, then it froze when I selected the options for power management.

After reboot, it asks the LUKS password, it shows the GNOME prompt to select the user, then the screen stays black while the CPU fan turns like mad. After a few minutes the CapsLock key light starts blinking.

I’ve tried to boot at GRUB with a previous kernel version but it does the same, except for the CapsLock key light.

The laptop has a Nvidia GEForce GTX 560m, might the cause be a wrong graphic driver?


EDIT 1: I removed the nouveau driver and installed the appropriate Nvidia graphic driver as described here. System is set to boot to multi-user.target.

Now when I run startx the screen goes black for a split second and then outputs the following error:

xauth:  file /home/dr/.serverauth.6309 does not exist


X.Org X Server 1.20.1
X Protocol Version 11, Revision 0
Build Operating System:  3.10.0-957.1.3.el7.x86_64
Current Operating System: Linux hackbox 3.10.0-957.10.1.el7.x86_64 #1 SMP Mon Mar 18 15:06:45 UTC 2019 x86_64
Kernel command line: BOOT_IMAGE=/vmlinuz-3.10.0-957.10.1.el7.x86_64 root=UUID=3a27c3be-ea50-4548-92db-53879292b3aa ro rd.luks.uuid=luks-fac75b1c-2869-4923-8ff1-0e7e7e868dd3 rd.luks.uuid=luks-735bf876-be70-40a4-ac81-f6c6ab46b542 rhgb quiet nouveau.modeset=0
Build Date: 14 March 2019  10:37:36AM
Build ID: xorg-x11-server 1.20.1-5.3.el7_6
Current version of pixman: 0.34.0
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Sat Mar 23 11:40:25 2019
(==) Using config directory: "/etc/X11/xorg.conf.d"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(II) modeset(0): Initializing kms color map for depth 24, 8 bpc.
xinit: connection to X server lost

waiting for X server to shut down (II) Server terminated successfully (0). Closing log file.

Here are the relevant lines from /var/log/Xorg.0.log, reporting only the lines with warnings or errors:

(...)
[   409.722] (II) modeset(0): using drv /dev/dri/card0
[   409.722] (WW) Falling back to old probe method for fbdev
[   409.722] (II) Loading sub module "fbdevhw"
[   409.722] (II) LoadModule: "fbdevhw"
[   409.722] (II) Loading /usr/lib64/xorg/modules/libfbdevhw.so
[   409.723] (II) Module fbdevhw: vendor="X.Org Foundation"
[   409.723]    compiled for 1.20.1, module version = 0.0.2
[   409.723]    ABI class: X.Org Video Driver, version 24.0
[   409.723] (EE) [drm] Failed to open DRM device for (null): -2
[   409.724] (II) modeset(0): Creating default Display subsection in Screen section
        "Default Screen Section" for depth/fbbpp 24/32
[   409.724] (==) modeset(0): Depth 24, (==) framebuffer bpp 32
[   409.724] (==) modeset(0): RGB weight 888
[   409.724] (==) modeset(0): Default visual is TrueColor
[   409.724] (II) Loading sub module "glamoregl"
[   409.724] (II) LoadModule: "glamoregl"
[   409.725] (WW) Warning, couldn't open module glamoregl
[   409.725] (EE) modeset: Failed to load module "glamoregl" (module does not exist, 0)
[   409.725] (EE) modeset(0): Failed to load glamor module.
(...)
[   409.766] (II) Initializing extension GLX
[   409.766] (EE) Failed to initialize GLX extension (Compatible NVIDIA X driver not found)
(...)

and the output of lsmod | grep nvidia :

nvidia_drm             39676  0
nvidia_modeset       1108588  1 nvidia_drm
nvidia              14368631  1 nvidia_modeset
ipmi_msghandler        56032  2 ipmi_devintf,nvidia
drm_kms_helper        179394  3 i915,nouveau,nvidia_drm
drm                   429744  6 ttm,i915,drm_kms_helper,nouveau,nvidia_drm

EDIT 2: It seems that glamoregl is part of the ATI driver framework and does not work with Nvidia. So I uninstalled xorg-x11-glamor (and reinstalled xorg-x11-server which was deleted as a dependency).

Now startx starts Gnome but it is unresponsive: it doesn’t accept any keypress, and the mouse pointer doesn’t move. The system isn’t frozen or crashed though, because the clock in the upper right corner works.


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#StackBounty: #linux #centos #password #expired #xrdp Issues with expired passwords using XRDP in CentOS

Bounty: 100

I am running a series of docker containers running an xfce desktop which can only be accessed via xrdp. I set password restrictions and expired the current passwords of all users expecting to get a prompt through xrdp on the next login to change the password.

I would expect, once the user enters their (now expired) password they would be prompted to change the password and it would allow a login. xrdp, however, simply fails with a “login failed for display 0”.

Is there a setting I’m missing within xrdp that would allow for password reset / changes on login?


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#StackBounty: #linux #networking #centos #monitoring How to show realtime traffic on each virtual network interface?

Bounty: 300

I have a dedicated server with a few virtual network interfaces, each mapped to a public IP address. How can I monitor the realtime traffic (in packets/s or Mb/s) of each of them, ideally on a single screen?

What I’m looking for is something like:

eth0:0 123 packets/s
eth0:1 234 packets/s
eth0:2 345 packets/s

I tried iptraf, iftop, jnettop, but I could not get any of them to group the display by virtual interface: they all show the whole eth0.

Note that I’m open to other tools, as long as they’re available on CentOS (+ EPEL / remi).


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#StackBounty: #hard-drive #centos #ext4 Getting an “is not a block special device.” error when trying to mount an 8TB disk in CentOS 7.6

Bounty: 50

I’m trying to format and mount a 8TB external as an ext4 and it doesn’t seem to work right.

I can create my partition using gdisk:

sdc               8:32   0   7.3T  0 disk
└─sdc1            8:33   0   7.3T  0 part

But when I create the filesystem I get a weird error that says: “/dev/sdc1 is not a block special device.” however it seems to complete:

# mke2fs -t ext4 /dev/sdc1
mke2fs 1.42.9 (28-Dec-2013)
/dev/sdc1 is not a block special device.
Proceed anyway? (y,n) y
Discarding device blocks: done
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
246512 inodes, 984801 blocks
49240 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1008730112
31 block groups
32768 blocks per group, 32768 fragments per group
7952 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736

Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done

Afterwards though, when mounting it doesn’t seem to work and it mounts /dev/loop0 instead? I’m not even sure what that is and the filesystem is the wrong size.

/dev/loop0               4.0G   16M  3.7G   1% /mnt/test

I was reading apparently this is some new type of drive with sectors not in the normal place? Any help would be appreciated.


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