RHEL 9 - What's new
Python2 gone
Python version 2 is no longer available as of RHEL9. All python programs must be converted to python-3.9 or later, or contained in a coda or other such environment.
Video Conferencing
If you need to use Microsoft Teams for video conferencing, the best option is to use chromium-browser as your default browser. This should allow you to click on URLs and open teams. Firefox has problems with sound and video in Mircosoft Teams.
xv gone
The image viewing program called xv is no longer available. Alternative image viewing programs include eog, gthumb, and display. For manipulating images, gimp is available.
Remote Desktop
In RHEL8 the command xfreerdp was used to connect to Windows desktops. The replacement is called remmina and here are some examples...
This will connect you to the login screen of aoctsa
remmina -c rdp://aoctsa.ad.nrao.edu
This will connect you to gbtsa as user krowe in full screen mode
remmina -c rdp://ad\\krowe@gbtsa.ad.nrao.edu --enable-fullscreen
VNC server
RHEL now ships the tigerVNC systemd unit to run a VNC login server. The vncserver command still works but a deprecation message is displayed.
SSH to RHEL6
If you ssh to an RHEL6 or older machine from RHEL9 you may see the error Bad server host key: Invalid key length. This is because the host keys on RHEL6 are too old for RHEL9 to accept by default.
Solution: Use the following option to ssh -o RSAMinSize=1024 For example
ssh -o RSAMinSize=1024 cmibhost-vml
/var/spool/mail is gone
Since NRAO transitioned to Microsoft Office365 for email in late 2023, the old inboxes in /var/spool/mail became inactive and only receive email messages in the rarest of instances. Because of this, RHEL9 no longer has these mail boxes available via /var/spool/mail. If you still need access to these old mail boxes you can access them via /home/mail but even that may be removed in the near future.
mutt -f /home/mail/$USER
Support for x86_64-v1 is gone
RHEL9 no longer supports v1 of the x86_64 instruction set. This includes CPUs before the Intel Nehalem processors which were introduced in 2008. RHEL10 will drop support for x86_64-v2 which includes CPUs before the Intel Haswell processors which were introduced in 2013.
