Hi everyone. I am trying to get multiple VNC sessions going on my machine. I am using RHEL PPC64 and have followed the tigerVNC directions 100% found on the RHEL site for setting up VNC sessions.

On my RHEL installation, I have installed a client that uses autofx, nfs, ldap, and openssl that allows me to connect my machine to a system for authentication as well as redirection my home directories to an NFS location.

I am successfully able to get ONE user working on a vnc session. However, any time I try to run TWO or more vnc sessions, the 2nd session always crashes and will not run.

Here is what my service file looks like... As you can see, I am using pam_service=vnc in order to authenticate by vnc session to my ldap server.

[Unit]
Description=Remote desktop service (VNC)
After=syslog.target network.target

[Service]
Type=simple

Clean any existing files in /tmp/.X11-unix environment

ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
ExecStart=/usr/sbin/runuser -l bboone -c "/usr/bin/vncserver %i -geometry 1920x1030 -SecurityTypes=VeNCrypt,TLSPlain -PlainUsers=$USER pam_service=vnc"
PIDFile=/gsa/tucgsa/home/b/b/bboone/.vnc/%H%i.pid
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'

[Install]
WantedBy=multi-user.target

Here is the output of /var/log/messages when I try to run it....

pr 10 16:00:01 obi systemd: Started Session 29 of user root.
Apr 10 16:00:01 obi systemd: Starting Session 29 of user root.
Apr 10 16:00:01 obi systemd: Removed slice User Slice of root.
Apr 10 16:00:01 obi systemd: Stopping User Slice of root.
Apr 10 16:01:01 obi systemd: Created slice User Slice of root.
Apr 10 16:01:01 obi systemd: Starting User Slice of root.
Apr 10 16:01:01 obi systemd: Started Session 30 of user root.
Apr 10 16:01:01 obi systemd: Starting Session 30 of user root.
Apr 10 16:01:01 obi systemd: Removed slice User Slice of root.
Apr 10 16:01:01 obi systemd: Stopping User Slice of root.
Apr 10 16:03:19 obi systemd: Starting Remote desktop service (VNC)...
Apr 10 16:03:19 obi systemd: Started Remote desktop service (VNC).
Apr 10 16:03:19 obi systemd: Started Session c9 of user jshioya.
Apr 10 16:03:19 obi systemd: Starting Session c9 of user jshioya.
Apr 10 16:03:21 obi runuser: Set PATH for Linux Build Tools!
Apr 10 16:03:25 obi runuser: WARNING: The first attempt to start Xvnc failed, possibly because the font
Apr 10 16:03:25 obi runuser: catalog is not properly configured. Attempting to determine an appropriate
Apr 10 16:03:25 obi runuser: font path for this system and restart Xvnc using that font path ...
Apr 10 16:03:28 obi runuser: Could not start Xvnc.
Apr 10 16:03:28 obi runuser: _XSERVTransmkdir: Owner of /tmp/.X11-unix should be set to root
Apr 10 16:03:28 obi runuser: Xvnc TigerVNC 1.8.0 - built Oct 12 2017 09:23:32
Apr 10 16:03:28 obi runuser: Copyright (C) 1999-2017 TigerVNC Team and many others (see README.txt)
Apr 10 16:03:28 obi runuser: See http://www.tigervnc.org for information on TigerVNC.
Apr 10 16:03:28 obi runuser: Underlying X server release 11903000, The X.Org Foundation
Apr 10 16:03:28 obi runuser: Tue Apr 10 16:03:22 2018
Apr 10 16:03:28 obi runuser: vncext: VNC extension running!
Apr 10 16:03:28 obi runuser: vncext: Listening for VNC connections on all interface(s), port 5942
Apr 10 16:03:28 obi runuser: vncext: created VNC server for screen 0
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:28 obi runuser: (EE) Backtrace:
Apr 10 16:03:28 obi runuser: (EE) 0: /usr/bin/Xvnc (xorg_backtrace+0x90) [0x10255900]
Apr 10 16:03:28 obi runuser: (EE) 1: /usr/bin/Xvnc (0x10000000+0x25ae5c) [0x1025ae5c]
Apr 10 16:03:28 obi runuser: (EE) 2: (vdso) (__kernel_sigtramp_rt64+0x0) [0x3fffa5a40478]
Apr 10 16:03:28 obi runuser: (EE) 3: /lib64/ld64.so.2 (0x3fffa5a60000+0x7174) [0x3fffa5a67174]
Apr 10 16:03:28 obi runuser: (EE) 4: /lib64/ld64.so.2 (0x3fffa5a60000+0xb5f0) [0x3fffa5a6b5f0]
Apr 10 16:03:28 obi runuser: (EE) 5: /lib64/ld64.so.2 (0x3fffa5a60000+0x1bff0) [0x3fffa5a7bff0]
Apr 10 16:03:28 obi runuser: (EE) 6: /lib64/ld64.so.2 (0x3fffa5a60000+0x15cc0) [0x3fffa5a75cc0]
Apr 10 16:03:28 obi runuser: (EE) 7: /lib64/ld64.so.2 (0x3fffa5a60000+0x1b4cc) [0x3fffa5a7b4cc]
Apr 10 16:03:28 obi runuser: (EE) 8: /usr/lib64/libdl.so.2 (0x3fffa5720000+0x1138) [0x3fffa5721138]
Apr 10 16:03:28 obi runuser: (EE) 9: /lib64/ld64.so.2 (0x3fffa5a60000+0x15cc0) [0x3fffa5a75cc0]
Apr 10 16:03:28 obi runuser: (EE) 10: /usr/lib64/libdl.so.2 (0x3fffa5720000+0x1c18) [0x3fffa5721c18]
Apr 10 16:03:28 obi runuser: (EE) 11: /usr/lib64/libdl.so.2 (dlopen+0x48) [0x3fffa5721238]
Apr 10 16:03:28 obi runuser: (EE) 12: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x45b4bc) [0x3fffa34eb4bc]
Apr 10 16:03:28 obi runuser: (EE) 13: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x469acc) [0x3fffa34f9acc]
Apr 10 16:03:28 obi runuser: (EE) 14: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x81f388) [0x3fffa38af388]
Apr 10 16:03:28 obi runuser: (EE) 15: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x62d38) [0x3fffa30f2d38]
Apr 10 16:03:28 obi runuser: (EE) 16: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x55212c) [0x3fffa35e212c]
Apr 10 16:03:28 obi runuser: (EE) 17: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x551e88) [0x3fffa35e1e88]
Apr 10 16:03:28 obi runuser: (EE) 18: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x3e2bfc) [0x3fffa3472bfc]
Apr 10 16:03:28 obi runuser: (EE) 19: /usr/lib64/dri/swrast_dri.so (0x3fffa3090000+0x3de7c4) [0x3fffa346e7c4]
Apr 10 16:03:28 obi runuser: (EE) 20: /usr/bin/Xvnc (0x10000000+0xa9860) [0x100a9860]
Apr 10 16:03:28 obi runuser: (EE) 21: /usr/bin/Xvnc (GlxExtensionInit+0x284) [0x100a83a4]
Apr 10 16:03:28 obi runuser: (EE) 22: /usr/bin/Xvnc (InitExtensions+0x90) [0x10052580]
Apr 10 16:03:28 obi runuser: (EE) 23: /usr/bin/Xvnc (dix_main+0x2a8) [0x101f0cc8]
Apr 10 16:03:28 obi runuser: (EE) 24: /usr/bin/Xvnc (main+0x18) [0x1004ca88]
Apr 10 16:03:28 obi runuser: (EE) 25: /usr/lib64/libc.so.6 (0x3fffa4e10000+0x24980) [0x3fffa4e34980]
Apr 10 16:03:28 obi runuser: (EE) 26: /usr/lib64/libc.so.6 (__libc_start_main+0xc4) [0x3fffa4e34b74]
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:28 obi runuser: (EE) Segmentation fault at address 0x3fffa5a9fe28
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:28 obi runuser: Fatal server error:
Apr 10 16:03:28 obi runuser: (EE) Caught signal 11 (Segmentation fault). Server aborting
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:28 obi runuser: _XSERVTransmkdir: Owner of /tmp/.X11-unix should be set to root
Apr 10 16:03:28 obi runuser: Xvnc TigerVNC 1.8.0 - built Oct 12 2017 09:23:32
Apr 10 16:03:28 obi runuser: Copyright (C) 1999-2017 TigerVNC Team and many others (see README.txt)
Apr 10 16:03:28 obi runuser: See http://www.tigervnc.org for information on TigerVNC.
Apr 10 16:03:28 obi runuser: Underlying X server release 11903000, The X.Org Foundation
Apr 10 16:03:28 obi runuser: Tue Apr 10 16:03:25 2018
Apr 10 16:03:28 obi runuser: vncext: VNC extension running!
Apr 10 16:03:28 obi runuser: vncext: Listening for VNC connections on all interface(s), port 5942
Apr 10 16:03:28 obi runuser: vncext: created VNC server for screen 0
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:28 obi runuser: (EE) Backtrace:
Apr 10 16:03:28 obi runuser: (EE) 0: /usr/bin/Xvnc (xorg_backtrace+0x90) [0x10255900]
Apr 10 16:03:28 obi runuser: (EE) 1: /usr/bin/Xvnc (0x10000000+0x25ae5c) [0x1025ae5c]
Apr 10 16:03:28 obi runuser: (EE) 2: (vdso) (__kernel_sigtramp_rt64+0x0) [0x3fffadb20478]
Apr 10 16:03:28 obi runuser: (EE) 3: /lib64/ld64.so.2 (0x3fffadb40000+0x7174) [0x3fffadb47174]
Apr 10 16:03:28 obi runuser: (EE) 4: /lib64/ld64.so.2 (0x3fffadb40000+0xb5f0) [0x3fffadb4b5f0]
Apr 10 16:03:28 obi runuser: (EE) 5: /lib64/ld64.so.2 (0x3fffadb40000+0x1bff0) [0x3fffadb5bff0]
Apr 10 16:03:28 obi runuser: (EE) 6: /lib64/ld64.so.2 (0x3fffadb40000+0x15cc0) [0x3fffadb55cc0]
Apr 10 16:03:28 obi runuser: (EE) 7: /lib64/ld64.so.2 (0x3fffadb40000+0x1b4cc) [0x3fffadb5b4cc]
Apr 10 16:03:28 obi runuser: (EE) 8: /usr/lib64/libdl.so.2 (0x3fffad800000+0x1138) [0x3fffad801138]
Apr 10 16:03:28 obi runuser: (EE) 9: /lib64/ld64.so.2 (0x3fffadb40000+0x15cc0) [0x3fffadb55cc0]
Apr 10 16:03:28 obi runuser: (EE) 10: /usr/lib64/libdl.so.2 (0x3fffad800000+0x1c18) [0x3fffad801c18]
Apr 10 16:03:28 obi runuser: (EE) 11: /usr/lib64/libdl.so.2 (dlopen+0x48) [0x3fffad801238]
Apr 10 16:03:28 obi runuser: (EE) 12: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x45b4bc) [0x3fffab5cb4bc]
Apr 10 16:03:28 obi runuser: (EE) 13: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x469acc) [0x3fffab5d9acc]
Apr 10 16:03:28 obi runuser: (EE) 14: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x81f388) [0x3fffab98f388]
Apr 10 16:03:28 obi runuser: (EE) 15: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x62d38) [0x3fffab1d2d38]
Apr 10 16:03:28 obi runuser: (EE) 16: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x55212c) [0x3fffab6c212c]
Apr 10 16:03:28 obi runuser: (EE) 17: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x551e88) [0x3fffab6c1e88]
Apr 10 16:03:28 obi runuser: (EE) 18: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x3e2bfc) [0x3fffab552bfc]
Apr 10 16:03:28 obi runuser: (EE) 19: /usr/lib64/dri/swrast_dri.so (0x3fffab170000+0x3de7c4) [0x3fffab54e7c4]
Apr 10 16:03:28 obi runuser: (EE) 20: /usr/bin/Xvnc (0x10000000+0xa9860) [0x100a9860]
Apr 10 16:03:28 obi runuser: (EE) 21: /usr/bin/Xvnc (GlxExtensionInit+0x284) [0x100a83a4]
Apr 10 16:03:28 obi runuser: (EE) 22: /usr/bin/Xvnc (InitExtensions+0x90) [0x10052580]
Apr 10 16:03:28 obi runuser: (EE) 23: /usr/bin/Xvnc (dix_main+0x2a8) [0x101f0cc8]
Apr 10 16:03:28 obi runuser: (EE) 24: /usr/bin/Xvnc (main+0x18) [0x1004ca88]
Apr 10 16:03:28 obi runuser: (EE) 25: /usr/lib64/libc.so.6 (0x3fffacef0000+0x24980) [0x3fffacf14980]
Apr 10 16:03:28 obi runuser: (EE) 26: /usr/lib64/libc.so.6 (__libc_start_main+0xc4) [0x3fffacf14b74]
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:28 obi runuser: (EE) Segmentation fault at address 0x3fffadb7fe28
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:28 obi runuser: Fatal server error:
Apr 10 16:03:28 obi runuser: (EE) Caught signal 11 (Segmentation fault). Server aborting
Apr 10 16:03:28 obi runuser: (EE)
Apr 10 16:03:53 obi systemd-logind: Failed to abandon session scope: Connection timed out
Apr 10 16:03:53 obi systemd: vncserver-jshioya@:42.service: main process exited, code=exited, status=255/n/a
Apr 10 16:03:53 obi systemd: Unit vncserver-jshioya@:42.service entered failed state.
Apr 10 16:03:53 obi systemd: vncserver-jshioya@:42.service failed.

Just to reiterate, I am fully able to get one user to work fine. But when I try to run 2 users, the second process always crashes and does not work. Please advise.