NxFrameBuffer error while starting

[JustAnotherLinuxGuy]

Hello,

I’ve tried searching this forum for an answer, but I’m still having trouble getting my VM to launch. I am on Ubuntu 22.04.4 GNOME desktop, attempting to launching a Debian based VM (no physical display) with GNOME 46 desktop. I am using the latest free version of NoMachine

The error I see in nxserver.log is:

Info: Handler started with pid 1214 on Tue May 21 14:32:05 2024.

Info: Handling connection from 127.0.0.1 port 45164 on Tue May 21 14:32:05 2024.

1214 1214 2024-05-21 14:32:08 166.686 NXSERVER WARNING! Process ‘/usr/NX/bin/nxexec –isadmin DV9G49’ with pid ‘1245/1245’ finished with exit code 1 after 0,031 seconds.

1214 1214 2024-05-21 14:32:08 168.653 NXSERVER User ‘DV9G49’ logged in from ‘127.0.0.1’ using authentication method NX-password.

1250 1250 2024-05-21 14:32:09 405.199 NXSERVER Connected from remote machine ‘127.0.0.1’ using protocol ‘NX’.

1252 1252 2024-05-21 14:32:09 412.737 NXSERVER Connected from remote machine ‘127.0.0.1’ using protocol ‘NX’.

1214 1214 2024-05-21 14:32:09 637.075 NXSERVER ERROR! Received error from nxserver –daemon nxFrameBuffer error while starting

1270 1270 2024-05-21 14:32:40 389.613 NXSERVER Connected from remote machine ‘127.0.0.1’ using protocol ‘NX’.

1280 1280 2024-05-21 14:33:11 279.170 NXSERVER Connected from remote machine ‘127.0.0.1’ using protocol ‘NX’.

Is there a setting configuration I am missing in either server.cfg or node.cfg? I’m not sure what other relevant information to include, please let me know if there is something else I can add that might help me figure this out.

[Britgirl]

Hi, can you send us the logs?
It’s better to enable debug first, before reproducing the problem. Full instructions on how to gather logs can be found here:

https://kb.nomachine.com/DT07S00243

Also, if it’s Gnome which is failing, check for errors in “.xsession-errors” and system logs (journalctl). Attach these along with NoMachine logs and send to forum[at]nomachine[dot]com.

[JustAnotherLinuxGuy]

Hi,

I am not able to compress the directory per the instructions in your KB, running

sudo tar -cvp --exclude 'cache*' --exclude 'images' --exclude 'temp' -f - path_to_user_home/.nx | gzip -c nxdir.tar.gz

returns “no such file or directory” Here is how I have it listed, but despite adjusting the name in the above command, I am unable to compress the files or the directory

drwx—— 11 user user 4.0K Feb 27 20:51 .nx

[Britgirl]

Hi, for the logs from the NoMachine server you are connecting to you should run:

$ sudo /etc/NX/nxserver --debug --collect

If you are the root user, run the command above without ‘sudo’.

The log archive is named as: NoMachine-log-.zip (e.g. NoMachine-log-2018.09.27-11.44.01.zip) and stored in: /usr/NX/var/log/archives.

sudo tar -cvp --exclude 'cache*' --exclude 'images' --exclude 'temp' -f - path_to_user_home/.nx | gzip -c nxdir.tar.gz

For the moment, we do not need logs from the device you are connecting from. You would need to replace path_to_user_home, usually its “/home/username”, but it depends on the username and system path where user’s home directories are stored.

[JustAnotherLinuxGuy]

Hello,

I have attached the logs as requested. Please let me know if there is anything else you need.

Attachments:

1. NoMachine-log-2024.05.23-15.28.49.zip

[Britgirl]

3093 3093 2024-05-23 15:28:39 406.174 NXSERVER Read 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n' 78 from FD#16.

There are some permission denials occurring when NoMachine attempts to create the .nx directory in the user’s home. Check that user DV9G49 has rights to create it.

An option is to set the path by using the key below, in node.cfg
#UsersDirectoryPath ""

# Specify a different path to the default home to create the .nx
# directory for storing session files and user's logs. This doesn't
# apply to the nx user, the NoMachine reserved user necessary for
# internal operation. If it doesn't exist yet, a sub-directory is
# created for the user who's starting a session, named as username.
# The .nx directory is created under that sub-directory. E.g. if this
# key is set to /tmp/nxdir/, when user nxtest runs the first session,
# the /tmp/nxdir/nxtest/.nx will be created. The directory specifed
# in the UsersDirectoryPath key should be writeable for all users or
# alternatively, the administrator should create a directory with
# proper ownership and permissions, named as username, for each of
# the users who need to start sessions there.
#
#UsersDirectoryPath ""

[JustAnotherLinuxGuy]

Yes I’m aware but that is not the concern I have at the moment. Even when that error wasn’t there, we are still unable to connect to the VM. The only error we could find was: “NxFrameBuffer error while starting” So I know that the directories permission isn’t the cause, as I mentioned, we were seeing the error prior to this permissions issue.

[JustAnotherLinuxGuy]

Hi,

Do you have any further suggestions on what we can do? We are stuck, and I have not been able to move past this error message and launch the VM

[Britgirl]

This is the log extract which shows the problem with permissions.

These are the only errors that are actually showing:

2959 2959 2024-05-23 15:27:03 985.560 NXSERVER Process initialized with arguments '--virtualsession --sessionid 9C179A65C3D88C951906D21B49D48B78'.
2959 2959 2024-05-23 15:27:04 685.161 NXSERVER Read 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n' 78 from FD#16.
2959 2959 2024-05-23 15:27:04 685.247 NXSERVER Handling connection error 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'.
2959 2959 2024-05-23 15:27:04 685.409 NXSERVER ERROR! Received error message from node ':', 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'
3002 3002 2024-05-23 15:27:35 601.923 NXSERVER Process initialized with arguments '--virtualsession --sessionid 2014DAC8AE6D73DF2E5952BC9823277F'.
3002 3002 2024-05-23 15:27:36 242.431 NXSERVER Read 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n' 78 from FD#16.
3002 3002 2024-05-23 15:27:36 242.490 NXSERVER Handling connection error 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'.
3002 3002 2024-05-23 15:27:36 242.659 NXSERVER ERROR! Received error message from node ':', 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'
3045 3045 2024-05-23 15:28:07 166.900 NXSERVER Process initialized with arguments '--virtualsession --sessionid 7575FB0F58880F0183A9C512A67CDAB7'.
3045 3045 2024-05-23 15:28:07 841.607 NXSERVER Read 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n' 78 from FD#16.
3045 3045 2024-05-23 15:28:07 841.690 NXSERVER Handling connection error 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'.
3045 3045 2024-05-23 15:28:07 841.894 NXSERVER ERROR! Received error message from node ':', 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'
3093 3093 2024-05-23 15:28:38 714.884 NXSERVER Process initialized with arguments '--virtualsession --sessionid 42222011AFC14FECB63EB0041331FCD2'.
3093 3093 2024-05-23 15:28:39 406.174 NXSERVER Read 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n' 78 from FD#16.
3093 3093 2024-05-23 15:28:39 406.258 NXSERVER Handling connection error 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'.
3093 3093 2024-05-23 15:28:39 406.409 NXSERVER ERROR! Received error message from node ':', 'NX> 596 Error: Cannot create /rhome/DV9G49/.nx. Error is 'Permission denied'.\n'
3137 3137 2024-05-23 15:28:49 903.362 NXSERVER Process initialized with arguments '--debug --collect'.

From the logs you sent us it shows that the frame buffer cannot start because of the home directory error.

[JustAnotherLinuxGuy]

So what if I tell you (again) that we were seeing the frame buffer error even without the permissions error? What would be causing it then, if the permission error is removed? I have tried removing that directory from the config file, but the error won’t go away for some reason. I will try clearing the permission error and uploading the logs.

[Britgirl]

we were seeing the frame buffer error even without the permissions error? What would be causing it then, if the permission error is removed?

Then yes we need to see the logs without the permissions error. Send them over and we’ll check.

[JustAnotherLinuxGuy]

Hi,

I have attempted to remove the directory settings in server.cfg. But despite my attempts at doing so, it appears the permissions error is still populating in the logs.

#
# Set the home directory for NX users. If an empty value is specified,
# NX Server will create the user's home in the default directory
# set on the system.
#
UserHome ""

If I’m not mistaken that is the setting I should adjust, correct? I had it disabled (commented out) and then enabled but with an empty value, as shown above. Either way, the permission error still appears in the log. I have even attempted to restart the services using /usr/NX/bin/nxserver --restart but that did not appear to help at all.

In any case, I have attached the logs, perhaps I am seeing an old message prior to my changes?

Attachments:

1. NoMachine-log-2024.05.31-13.50.51.zip

[Britgirl]

The same errors are present showing it’s not possible to write to the home directory. NoMachine detects that it’s headless (no x server running) and, as expected, tries to create its own virtual display. But since permissions are not set correctly, it fails.

Also, can you show us the output of the ls -la command for each of these?

/rhome/

/home/DV9G49

/rhome/DV9G49/.nx

You mentioned creating a virtual machine with Debian, what are you using to do that?

[JustAnotherLinuxGuy]

I have attempted to update the setting that prevents this directory from being created. I updated this setting in server.cfg and the relevant setting in node.cfg. But as I mentioned, despite making changes and restarting the service, the permissions error still appears. Why would that be, if I made specific changes on the config files?

This VM was created using Dockerfile, hosted in Google Cloud’s Workstations (used for VDI).

Please note, we intend to use /rhome as the main directory, we are mounting this directory to a GCP bucket using Filestore. So the /home/DV9G49 directory is irrelevant to us.

`root@workstation-analyst3:~# ls -la /rhome/
total 736
drwxr-xr-x 15 root root 4096 May 31 14:36 .
drwxr-xr-x 1 root root 4096 May 31 13:26 ..
drwxr-xr-x 2 root root 4096 Feb 27 18:39 27M6PF
drwxr-xr-x 2 root root 4096 Feb 27 18:39 4E37FH
drwxr-xr-x 2 root root 4096 Feb 27 18:39 8ZC5XJ
drwxr-xr-x 2 root root 4096 Apr 30 15:57 DMDSX2
drwxr-xr-x 2 root root 4096 May 23 16:03 DV9G49
drwxr-xr-x 2 root root 4096 Feb 27 18:39 FKQZ4M
drwxr-xr-x 2 root root 4096 Feb 27 18:39 GQ4PNR
drwxr-xr-x 2 root root 4096 Feb 27 18:39 NB87HM
-rw-r–r– 1 root root 578188 May 31 14:36 NoMachine-log-2024.05.31-13.50.51.zip
drwxr-xr-x 2 root root 4096 Feb 27 18:39 RB85WW
drwxr-xr-x 2 root root 4096 Feb 27 18:39 TBS5RZ
drwxr-xr-x 2 root root 4096 Feb 27 18:39 YXM85D
drwxr-xr-x 2 root root 4096 Feb 27 18:39 ZXW4NR
drwx—— 2 root root 16384 Feb 24 15:10 lost+found

root@workstation-analyst3:~# ls -la /home/DV9G49
total 28
drwxr-xr-x 2 DV9G49 DV9G49 4096 Feb 27 14:52 .
drwxr-xr-x 16 root root 4096 Feb 27 14:52 ..
-rw-r–r– 1 DV9G49 DV9G49 220 Apr 23 2023 .bash_logout
-rw-r–r– 1 DV9G49 DV9G49 3526 Apr 23 2023 .bashrc
-rw-r–r– 1 DV9G49 DV9G49 5290 Jul 12 2023 .face
lrwxrwxrwx 1 DV9G49 DV9G49 5 Jul 12 2023 .face.icon -> .face
-rw-r–r– 1 DV9G49 DV9G49 807 Apr 23 2023 .profile

root@workstation-analyst3:~# ls -la /rhome/DV9G49/.nx
ls: cannot access ‘/rhome/DV9G49/.nx’: No such file or directory
root@workstation-analyst3:~#’

[Britgirl]

Can you share this dockerfile with us so we can check it? Send it directly to forum[at]nomachine[dot]com.

Similar topics have been submitted in the past

NXFrameBuffer failed to start in Docker

Problems with NoMachine in docker

Redis error after time

but in some cases users didn’t come back to us.

Edited: we have the following document for Docker users https://kb.nomachine.com/DT07S00242. Did you check this already?

[Author]

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