-- EmmanuelMomjian - 2022-08-15

Changes impacting scientific staff in RHEL7->RHEL8 migration

Introduction

RHEL7 is reaching end of life, and may no longer be supported by NRAO CIS. See https://access.redhat.com/support/policy/updates/errata for more information on Red Hat support, dates, etc., for the various versions. Because of this, and the fact that new hardaware (e.g., from DELL) may not support RHEL7, migrating to RHEL8 is necessary for all employees using computers with the Linux OS. As scientific staff, we have particular things that we do with our desktop machines that others in the observatory who are making this migration may not. We need to understand how the migration will impact these things that we do, in order to be prepared for the day when it happens, and to then work around them as efficiently as possible.

There are currently two public machines in Socorro that have been updated to RHEL8 and are available for testing. We are also keeping a list on a google spreasheet for staff to provide feedback regarding the software they use in RHEL7 and the availability/functionality in RHEL8. These two public maches are Mizar in room 211 and Megrez in room 209.

This wiki page is meant as a living document, so anybody that is testing RHEL8 and/or making this transition is welcome to edit the page with differences they have found, alternatives or workarounds to RHEL7 solutions, etc.

A page similar to this existed for the RHEL6->RHEL7 migration. I've linked it here for reference.

The List

1. (Lorant) the software page says that for vncviewer and x11vnc the NRAO supported way is fastx. Fastx runs on gygax and clearly has it drawbacks wrt vncviewer and x11vnc (ie it is not your desktop!) and gygax runs on RHEL7. Until there is access to fastx on an RHEL8 machine, we have no way to get experience or judge how it will satisfy our needs. Either way, we should still have vncviewer and x11vnc or a real equivalent supported properly (and not only fastx).
   • (EM) Pat noted that vncserver/vncviewer are not going away in RHEL8. vnc will continue in RHEL8, but it would become history in RHEL9.
   • (KG) You can connect to your screen using Wayland/gnome only (enable screen sharing under share in settings) then i can connect with remmina
2. (from Frazer) evince doesn't do what I need, at least the current version. Okular does. I found Okular when acroread disappeared in the last transition. Will look for another alternative and let you know if I find one.
   • (EM) Pat noted that Okular is an optional install on RHEL8. Okular is available in RHEL8 now.
   • (Lorant) Still don't know why acroread wasn't an option in RHEL7 and why it can't be installed in RHEL8 - all the others seem half-hearted stop-gaps for the functionality we ask for.
     • (EM) acroread 64bit is dead for linux. This is the reason we cannot have it anymore.
3. (Barry) mail, xmail, mutt do not work - I use them in scripts. Is there a replacement? (Note added 08/19/22) sendmail does most of what I want; it has a man entry, but program is not installed
   
   • (EM) Pat noted /usr/bin/mailx works (command line). If it doesn't on your system, a simple "dnf install mailx" (as root) will do the trick. And mutt is an optional install too.
   • (Barry) mailx executes - it just doesn't send mail, says it doesn't have privilege.
   • (EM) CIS informed me that these programs should work now under RHEL8.
4. (Barry) The directory /opt/local/etc does not exist. It contains useful stuff for the tcsh shell.. Pretty easy to work around.
   • (EM) Pat noted: May be a mount (/opt/local/etc is served centrally) missing. Or that those (NRAO-written) scripts haven't been reviewed for RHEL8.
5. (Tony P.) DA tools Block checker, SB Status report, and fixEB all work as expected. Time conversion tool would not launch, got a "Could not initialized application. The application has not been initialized" warning in a pop-up box.
6. (Tony P.) Software request for GIMP to be installed in the Graphics Applications folder.
   • (EM) Pat noted: GIMP is an optional install - a "dnf install gimp" as root will do the trick.
   • (EM) This should be available on RHEL8 now.
7. (Tony P.) Update to checking VLA Operations Tools under RHEL8 (14 Feb 2023): From obs.vla.nrao.edu (VLA Operations Tools)

• Scheduling Block Checker (production): will launch, you can enter the SB ID number and make adjustments to the starting LST range and parameters (e.g., maximum or minimum elevation). When clicked on the Run button it ran. However, there was no output display.
• Scheduling Block Checker (test): failed - "Fatal: Initialization Error: Could not initialize application. The application has not been initialized, for more information execute Java's from the command line."
• BlbpAlloc (production & test): failed - "Application SSA:Utilities: WIDAR Baseline Board Pair Assignment from https://ops.vla.nrao.edu/production/blbpAlloc/ is missing the permissions attribute. Applications without this attribute should not be trusted. Do you wish to allow this application to run?"
  Clicked on the NO button, then it reported: "Fatal: Initialization Error: Could not initialize application. The application has not been initialized, for more information execute Java's from the command line."

Command Line programs

• pressure (production & test): launched, failed - "Crashed with java.lang.OutOfMemory error: Java Heap Space". Note that the NRAO Logo was persistent on the screen and didn't go away after the program launched. Annoying.
• pressurePlotter (production & test): launched, failed and reported:
  SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder"
  SLF4J: Defaulting to no-operation (NOP) logger implementation
  SLF4J: see http://www.slf4j.org/codes.html#StaticLoggerBinder for more information
  Note that the NRAO Logo was persistent on the screen and didn't go away after the program launched. Annoying.
• In the schedsoc area, "graphMonth-py2" script just needs to be updated to python3.

• (From Eric) The .Xresources file replaces .Xdefaults file and one has to "xrdb -merge .Xresources" to get it to be used; it is not picked up automatically as it used to be.
  • (EM) This needs to be done manually. Everyone should move to Xresources.
• (From Drew) Some pipeline scripts (e.g., qaPass) don't work in RHEL8, and may not work at all in RHEL8.
  • (EM) CIS advised to have this followed up with the pipeline dev team.
• (From Drew) userformatdisk was not found on at least two RHEL8 machines (MEGREZ and HOKU).
  • (EM) Schlake will work on this
• (from Rick) The unavailability of xmgrace is very bad for his work and the work of a few others.
  • (EM) Schlake installed it on his RHEL8 machine, so it can be made available elewhere too.
• About KDE It is no longer in RHEL8 officially but can be installed via EPEL howto is given here https://fedoraproject.org/wiki/SIGs/KDE/EPEL