Red Hat Satellite 6.3.1 includes packages that supports Red Hat Enterprise Linux 7.5 as well as a variety of performance enhancements and general bug fixes.
Especially notable is the improvements in the performance of content views. In our tests we've seen publishing of a single content view on RHEL7 redunce in time by 43% and publishing of composite views reduced 95%. To put numbers to this 6.3.0 took 320 seconds to publish a composite view while 6.3.1 took 14 seconds to publish the same CV.
Promotion also was significantly improved. A group of 16 CVs were promoted in 977 seconds in 6.3.0 to 5.78 seconds in 6.3.1 - a 99% reduction in time to promote!
There are two errata for the server  and one for the hosts . The install ISOs will be updated next week.
Customers who have already upgrade to Satellite 6.3 should follow the instructions in the errata.
Customers who are on older versions of Satellite should refer to the Upgrading and Updating Red Hat Satellite Guide.
You may also want to consider using the Satellite Upgrade Helper if moving from Satellite 6.x to Satellite 6.3
Customers who have received hotfixes should verify the list below to ensure their hotfix is contained in the release before upgrading. Please reach out to Red Hat Support in these cases.
Fixes included in 6.3.1
The performance of Content View publishing and promotion has been improved. (BZ#1522912)
The performance of Ansible Tower inventory collection has been improved. (BZ#1437197)
Various performance and scale improvements have been made. (BZ#1553881, BZ#1553879, BZ#1532348, BZ#1553871)
Several upgrade issues from 6.2.x to 6.3 have been resolved. (BZ#1549502, BZ#1547607, BZ#1553279)
The installer now allow users to configure the SSL protocols used by Tomcat. (BZ#1544995)
Disconnected installations no longer attempt to install the oauth gem from a remote server. (BZ#1541885)
Users can now configure custom products not to use an HTTP Proxy when syncing content, and to only use the proxy for Red Hat Content. (BZ#1132980)
Restarting a pulp worker with running tasks caused the tasks to be in a broken state. This problem has been fixed. In such cases, tasks are stopped with warning "Task cancelled". (BZ#1552118)
Puppet modules which were built on MacOS machines can now be imported into Satellite. (BZ#1445625)
Previously, an API endpoint used by the SCAP Satellite plug-in failed to provide generated guides based on the selected profile. Consequently, Red Hat Satellite was not able to get information from the plug-in, and the Satellite UI was broken. With this update, handling of the API endpoint has been updated, and it is now possible to generate guides using this API endpoint again. (BZ#1480595)
Backups were failing with relative paths since 6.2.13. This regression has been fixed. (BZ#1544401)
Pulp workers became deadlocked when the PULP_MAX_TASKS_PER_CHILD setting was enabled. These workers now reconnect correctly. (BZ#1590906)
When installing the katello-ca-consumer package, the script restarted Docker. Consequently, running containers where stopped. With this update, the Docker service is reloaded not restarted. (BZ#1518289)
Users of Red Hat Satellite are advised to upgrade to these updated packages, which fix these bugs.
Satellite Migration from RHEL 6 to RHEL 7
As a reminder, Red Hat continues to strongly recommend your Satellite and Capsule Servers only be run on RHEL 7. There are several reasons why you should move your Satellite environment from RHEL 6 to RHEL 7 including enhanced performance and long term supportability.
Future releases of Satellite (6.3 and above) will only support RHEL 7 and above. In preparation for newer versions of Satellite you need to start thinking about how to move from older versions of RHEL to RHEL 7.
While RHEL 6 does support an in-place migration from RHEL 6 to RHEL 7, this migration mechanism is not supported when running Satellite on the RHEL host. Instead you will need to clone your Satellite environment from a host running RHEL 6 to another host running RHEL 7 .
Review the Satellite 6.2.13 release blog for more detailed information about moving your Satellite environment from RHEL 6 to RHEL 7. 6.2.13 includes some important features for capsule backup and recovery which helps to ease the movement from RHEL 6 to RHEL 7.