Are you planning an upgrade from RHEL 7.x to RHEL 8.x or RHEL 9.x? If so, please continue reading.
With the upcoming end-of-life date for RHEL 7.x (30JUN2024), many SAS 9.4 customers are looking to upgrade from RHEL 7.x to RHEL 8.x. Note that Red Hat offers an add on subscription for Extended Life Cycle Support for RHEL 7.9, see Announcing up to 4 years of Extended Life Cycle Support (ELS) for Red Hat Enterprise Linux 7.
If you are planning to do an upgrade in place (UIP) of RHEL 7.x to RHEL 8.x, please review the list of issues that SAS customers have run into:
- LDAPS configuration for sasauth failing in RHEL 8: See this blog post for symptom and workaround Re: SFTP, RSYNC or SCP not working via SAS Enterprise Guide 8.3 execu... - SAS Support Communities
- Starting with RHEL 7.6, UserIDs can no longer be all numeric values. All-numeric usernames in Red Hat Enterprise Linux - Red Hat Customer Portal
- RHEL 8 supports OSSL 1.1.1.
- In SAS 9.4M7, SAS delivers three instances of OpenSSL libraries for use by SAS Servers, the SAS Web Server and the SAS Web Infrastructure Postgres database.
- For SAS Servers, SAS 9.4M8 uses OpenSSL Libraries available from the Operating System.
- Authentication failures with PAM using pam_sss.so. In RHEL7, the default setting was ad_gpo_access_control = permissive which meant that sasauth was able to call into SSSD to authenticate. In RHEL8, the default has changed to “enforcing” and this will block sasauth. This requires an edit to /etc/sssd/sssd.conf to set the value back to permissive to allow authentication from SAS.
- RHEL Swappiness Algorithm default value changed in RHEL 8. Please review this Red Hat article Change in swap behavior between RHEL 7 and RHEL 8 kernels - Red Hat Customer Portal. There are two things that need to be done:
- The vm.swappiness is changed back a value of 10 (what it was for RHEL 7 and 6)
- cgroup swappiness issue is addressed already
We will add to this list as we learn more issues regarding doing a UIP from RHEL 7.x to RHEL 8.x.
SAS recommends that SAS 9.4 customers upgrade their operating systems in this order.
- Stand up new RHEL 8.x systems.
- 2Install SAS 9.4M8 on the new RHEL 8.x systems.
- Use the SAS Migration Utility be used to package that installation and deploy it to a machine running the upgraded operating system.
SAS defers to operating system manufacturers when it comes to the use of this operating system update method and consistent with the SAS Disaster Recover Policy, does not offer Standard Support for the SAS deployment after an operating system update in place.
If you (the customer) would like to try an Update in Place from RHEL 7.x to RHEL 8.x, please understand that SAS has not tested this capability. If you decide to proceed with a RHEL Update in Place:
- Attend all the Red Hat webinars on this topic.
- These webinars “require” the customer be at RHEL 7.9 with a validated/working applications.
- Follow the instructions from Red Hat, for example the guidance offered in the Red Hat Upgrading from RHEL 7 to RHEL 8 documentation.
