Convert from CentOS Linux 7 to Red Hat Enterprise Linux 7 with Convert2RHEL

[@mohridwan4309]

After convert CentOS to RHEL, can we use RHEL with Developer License no-cost?

[@RedHatEnterpriseLinux]

@@mohridwan4309 it depends on the usecase and Developer subscription. Generally, if these are production systems, you’ll want a paid RHEL subscription for them. Developer subscriptions cover developer usecases (systems that are used for developing software, test & QA). The one exception to this is the program designed for individuals, hobbists, or small companies, Developer for Individuals. It’s up to 16 systems can also be used for production usecases.

[@jaypii360]

How about if you planning to convert separate hosts having CentOS versions 4,5and 6 to RHEL 9?

[@scottmcbrien6535]

The conversion tool, convert2rhel, has never supported Centos Linux 4 or 5. CentOS Linux 6 support for the tool has ended (removed in February 2023). So for these versions, you'll want to install RHEL9 boxes and migrate your application and/or data from the older systems you are retiring.

[@PawanSingh-ww6zq]

How much time does it take to completely migrate one application using Centos to Red hat Enterprize Linux?

[@RedHatEnterpriseLinux]

In my experience, on a vanilla system with all its updates and 4gb ram and 2cpus, it takes between 15-20 minutes. Now the tricky part is that is from a vanilla VM - no data, no workloads. So, that'll scale up the more complex your system is. - Eric

[@scottmcbrien6535]

You can try it out for yourself: www.redhat.com/en/interactive-labs/migrate-red-hat-enterprise-linux-centos-linux Recently Red Hat added both pre-conversion analysis and conversion ability to Red Hat Insights as well.

[@galgeri2945]

is that possible to convert using rhel dvd?

[@scottmcbrien6535]

Potentially. The latest RHEL7.9 install iso was updated on June 20, but may not include all the packages of the same version as your CentOS Linux 7 system. It's worth a try, and if needed, pull additional updates from the Red Hat CDN into that repo (and remake the repo). Where you may have issues is if any of the packages trying to be converted are *newer* on the CentOS Linux 7 host than what is available in your RHEL package repository...

[@shahidmehmood6718]

is there any way to directly convert centos 7 to rhel 8

[@RedHatEnterpriseLinux]

You aren’t able to migrate directly. You’ll need to do a convert2rhel to RHEL 7, but from there, there is nothing stoping you from doing an in-place upgrade to RHEL 8. This can be done back to back and you can do it in a single maintenance window. - Eric

[@miguelchavarria9319]

today centos 7 is disabled, rhel search this ¿how i do...? My system show this: (ERROR) REMOVE_SPECIAL_PACKAGES::SPECIAL_PACKAGE_REMOVAL_FAILED - Failed to remove some packages necessary for the conversion. Description: The cause of this error is unknown, please look at the diagnosis for more information. Diagnosis: Couldn't download the centos-release-7-9.2009.0.el7.centos.x86_64 package. This means we will not be able to do a complete rollback and may put the system in a broken state. Check to make sure that the CentOS Linux repositories are enabled and the package is updated to its latest version. If you would rather disregard this check set the environment variable 'CONVERT2RHEL_INCOMPLETE_ROLLBACK=1'. Remediations: N/A

[@RedHatEnterpriseLinux]

Are you utilizing the Vault URLs for your conversion? vault.centos.org/

[@miguelchavarria9319]

@@RedHatEnterpriseLinux yes, but many messages appear before to apply conver2rhel

[@RedHatEnterpriseLinux]

@@miguelchavarria9319 ensure the centos system is fully updated. And as pointed out earlier, the system repositories are configured to use the packages from centos vault instead of the old, retired location. The error provided above is that it could not download the centos-release RPM. If the repos are updated, you might try to manually download the rpm from the machine using something like curl or wget and a url from navigating the centos vault. It could be some other issue is stopping the download (firewall rules, proxy configuration, etc.) and another tool may provide some alternate diagnostic messages.

[@elpiquin80]

NO es tan fácil ahora que ha sido deshabilitado el repo

[@scottmcbrien6535]

If you change your CentOS7 Linux repos to instead use the CentOS Vault URLs, it should work. We have updated our hands-on-lab to perform this step as part of our walkthrough of doing a conversion: www.redhat.com/en/interactive-labs/migrate-red-hat-enterprise-linux-centos-linux