{"id":2968,"date":"2025-01-11T16:18:14","date_gmt":"2025-01-12T00:18:14","guid":{"rendered":"https:\/\/www.cloudinsidr.com\/content\/?p=2968"},"modified":"2025-01-11T16:18:56","modified_gmt":"2025-01-12T00:18:56","slug":"upgrading-from-centos-6-to-centos-7-and-beyond","status":"publish","type":"post","link":"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/","title":{"rendered":"Upgrading from CentOS 6 to CentOS 7 and Beyond?"},"content":{"rendered":"

Upgrading from CentOS 6 to CentOS 7 involves a manual approach, as the standard <\/span>yum<\/span> update and migration paths won’t work anymore.\u00a0<\/span><\/p>\n

CentOS 6 to 7 upgrades are inherently risky, especially with outdated repositories. Consider migrating directly to a modern distribution like Rocky Linux or AlmaLinux. Tools like <\/span>ELevate <\/b>can help with migration from CentOS 6\/7 to newer distributions.<\/span><\/p>\n

The <\/span>ELevate Project<\/b> by AlmaLinux offers a community-supported tool for upgrading CentOS 7 to newer RHEL-based distributions. While it doesn\u2019t support CentOS 6 directly, you could consider upgrading from CentOS 6 to 7 first, then use ELevate for further upgrades.<\/span><\/p>\n

<\/p>\n

Here’s how you can perform the upgrade using available tools and workarounds.<\/span><\/p>\n

Step 1. Backup Your Data<\/b><\/h3>\n

It goes without saying that before you initiate the upgrade, you should mitigate the risk. Ensure that you have a complete backup of all your data, configurations, and applications. This step is crucial for your peace of mind. The upgrade process is not seamless, but wrought with pitfalls and surprises. If you are not careful, it might lead to data loss or system instability.<\/span><\/p>\n

Step 2. Download CentOS 7 ISO<\/b><\/h3>\n

Obtain the CentOS 7 ISO from a trusted archive like the CentOS Vault or a mirror site. Downlaod the ISO:<\/span><\/p>\n

wget <\/span>http:\/\/vault.centos.org\/7.9.2009\/isos\/x86_64\/CentOS-7-x86_64-DVD-2009.iso<\/span><\/pre>\n
Step 3. Point to Local Repositories<\/b><\/p>\n
Since the official CentOS 6 and 7 repositories will no longer work, you will need to use local repositories or those from a trusted CentOS mirror. Mount the CentOS 7 ISO as a local repository:<\/span><\/p>\n
mount -o loop CentOS-7-x86_64-DVD-2009.iso \/mnt<\/span>\r\n\r\ncat <<EOF > \/etc\/yum.repos.d\/centos7.repo<\/span>\r\n\r\n[centos7]<\/span>\r\nname=CentOS 7 Local Repo<\/span>\r\nbaseurl=file:\/\/\/mnt<\/span>\r\nenabled=1<\/span>\r\ngpgcheck=0<\/span>\r\nEOF<\/span><\/pre>\n
Step 4. Prepare for the Upgrade<\/b><\/h3>\n
Download and install the Red Hat Preupgrade Assistant a.k.a. the <\/span>preupg<\/span> tool (Preupgrade Assistant). You will need it to analyze your system’s compatibility:<\/span><\/p>\n
wget <\/span>http:\/\/mirror.centos.org\/centos\/6\/os\/x86_64\/Packages\/preupgrade-assistant*.rpm<\/span><\/del>\r\nwget http:\/\/vault.centos.org\/6.10\/os\/x86_64\/Packages\/preupgrade-assistant-2.6.3-1.el6.x86_64.rpm<\/span><\/pre>\n
rpm -ivh preupgrade-assistant*.rpm<\/span><\/pre>\n
Run the Preupgrade Assistant (in bash):<\/span><\/p>\n
preupg<\/span><\/pre>\n
This tool generates a report about potential issues with your upgrade. Review the output and address any major blockers.<\/span><\/p>\n
Step 5. Download redhat-upgrade-tool<\/b><\/p>\n
Install the Red Hat Upgrade Tool from a compatible mirror:<\/span><\/p>\n
wget http:\/\/mirror.centos.org\/centos\/6\/os\/x86_64\/Packages\/redhat-upgrade-tool*.rpm<\/span>\r\nrpm -ivh redhat-upgrade-tool*.rpm<\/span><\/pre>\n
Step 6. Begin the Upgrade<\/b><\/p>\n
Run the <\/span>redhat-upgrade-tool<\/span> to begin the upgrade process:<\/span><\/p>\n
redhat-upgrade-tool --network 7 --instrepo=file:\/\/\/mnt --cleanup-post<\/span><\/pre>\n
The <\/span>–instrepo<\/span> flag ensures the tool uses the ISO as the source for the upgrade.<\/span><\/p>\n
Step 7. The Wrap-Up: Post-Upgrade Steps<\/b><\/p>\n
After the upgrade, r<\/span>eboot your system into CentOS 7.<\/p>\n
Next, check the CentOS version to confirm the upgrade:<\/span><\/p>\n
cat \/etc\/centos-release<\/span><\/pre>\n
Check that all services and applications are running as expected. If not, disable SELinux temporarily and try again.<\/span><\/p>\n
Manually review and update configuration files located in \/etc.<\/span><\/p>\n
Then, update all packages using the CentOS 7 repositories (assuming they are still available):<\/span><\/p>\n
yum update<\/span><\/pre>\n
What\u00b4s next?<\/b><\/p>\n
ELevate (https:\/\/almalinux.org\/elevate\/) enables upgrades between major versions of RHEL derivatives. After performing an upgrade-in-place from CentOS 6.x to 7.x you could change the Linux flavour using ELevate and then go all the way through version 8.x of the RHEL derivative of your choice. Then, upgrade from 8.x to 9.x within the same derivative.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"
Upgrading from CentOS 6 to CentOS 7 involves a manual approach, as the standard yum update and migration paths won’t work anymore.\u00a0 CentOS 6 to 7 upgrades are inherently risky, especially with outdated repositories. Consider migrating directly to a modern distribution like Rocky Linux or AlmaLinux. Tools like ELevate can help with migration from CentOS […]<\/p>\n","protected":false},"author":1,"featured_media":2969,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[143,1],"tags":[55],"yoast_head":"\nUpgrading from CentOS 6 to CentOS 7 and Beyond? - CloudInsidr<\/title>\n<meta name=\"robots\" content=\"index, follow\" \/>\n<meta name=\"googlebot\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<meta name=\"bingbot\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Upgrading from CentOS 6 to CentOS 7 and Beyond? - CloudInsidr\" \/>\n<meta property=\"og:description\" content=\"Upgrading from CentOS 6 to CentOS 7 involves a manual approach, as the standard yum update and migration paths won’t work anymore.\u00a0 CentOS 6 to 7 upgrades are inherently risky, especially with outdated repositories. Consider migrating directly to a modern distribution like Rocky Linux or AlmaLinux. Tools like ELevate can help with migration from CentOS […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/\" \/>\n<meta property=\"og:site_name\" content=\"CloudInsidr\" \/>\n<meta property=\"article:published_time\" content=\"2025-01-12T00:18:14+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-01-12T00:18:56+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.cloudinsidr.com\/content\/wp-content\/uploads\/2025\/01\/elevate-white-letters-no-background.png\" \/>\n\t<meta property=\"og:image:width\" content=\"6890\" \/>\n\t<meta property=\"og:image:height\" content=\"3327\" \/>\n<meta name=\"twitter:card\" content=\"summary\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/#website\",\"url\":\"https:\/\/www.cloudinsidr.com\/content\/\",\"name\":\"CloudInsidr\",\"description\":\"Cyber security, infotech\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":\"https:\/\/www.cloudinsidr.com\/content\/?s={search_term_string}\",\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/#primaryimage\",\"inLanguage\":\"en-US\",\"url\":\"https:\/\/www.cloudinsidr.com\/content\/wp-content\/uploads\/2025\/01\/elevate-white-letters-no-background.png\",\"width\":6890,\"height\":3327},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/#webpage\",\"url\":\"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/\",\"name\":\"Upgrading from CentOS 6 to CentOS 7 and Beyond? - CloudInsidr\",\"isPartOf\":{\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/#primaryimage\"},\"datePublished\":\"2025-01-12T00:18:14+00:00\",\"dateModified\":\"2025-01-12T00:18:56+00:00\",\"author\":{\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/#\/schema\/person\/dd6ee9cb21cf05763fd7cff3d6f11b2b\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.cloudinsidr.com\/content\/upgrading-from-centos-6-to-centos-7-and-beyond\/\"]}]},{\"@type\":[\"Person\"],\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/#\/schema\/person\/dd6ee9cb21cf05763fd7cff3d6f11b2b\",\"name\":\"Cloud Insidr\",\"image\":{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.cloudinsidr.com\/content\/#personlogo\",\"inLanguage\":\"en-US\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/8b2fa1415b3d573b97d818b8f8f83b7c?s=96&d=mm&r=g\",\"caption\":\"Cloud Insidr\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","_links":{"self":[{"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/posts\/2968"}],"collection":[{"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/comments?post=2968"}],"version-history":[{"count":3,"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/posts\/2968\/revisions"}],"predecessor-version":[{"id":2972,"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/posts\/2968\/revisions\/2972"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/media\/2969"}],"wp:attachment":[{"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/media?parent=2968"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/categories?post=2968"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cloudinsidr.com\/content\/wp-json\/wp\/v2\/tags?post=2968"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}