{"action":"created","issue":{"url":"https://api.github.com/repos/kaorimatz/packer-templates/issues/1","labels_url":"https://api.github.com/repos/kaorimatz/packer-templates/issues/1/labels{/name}","comments_url":"https://api.github.com/repos/kaorimatz/packer-templates/issues/1/comments","events_url":"https://api.github.com/repos/kaorimatz/packer-templates/issues/1/events","html_url":"https://github.com/kaorimatz/packer-templates/issues/1","id":96368097,"number":1,"title":"Centos 7 build kernel panics after first restart.","user":{"login":"ChiperSoft","id":231157,"avatar_url":"https://avatars.githubusercontent.com/u/231157?v=3","gravatar_id":"","url":"https://api.github.com/users/ChiperSoft","html_url":"https://github.com/ChiperSoft","followers_url":"https://api.github.com/users/ChiperSoft/followers","following_url":"https://api.github.com/users/ChiperSoft/following{/other_user}","gists_url":"https://api.github.com/users/ChiperSoft/gists{/gist_id}","starred_url":"https://api.github.com/users/ChiperSoft/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ChiperSoft/subscriptions","organizations_url":"https://api.github.com/users/ChiperSoft/orgs","repos_url":"https://api.github.com/users/ChiperSoft/repos","events_url":"https://api.github.com/users/ChiperSoft/events{/privacy}","received_events_url":"https://api.github.com/users/ChiperSoft/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-07-21T17:06:53Z","updated_at":"2015-07-22T15:58:54Z","closed_at":null,"body":"Initial install runs, system restarts to run the provisioning scripts, and immediately kernel panics.\r\n\r\n    VFS: Unable to mount root fs on unknown-block(0,0)\r\n\r\n- Packer 0.8.2\r\n- Vagrant 1.7.4\r\n- Virtualbox 5.0.0"},"comment":{"url":"https://api.github.com/repos/kaorimatz/packer-templates/issues/comments/123770179","html_url":"https://github.com/kaorimatz/packer-templates/issues/1#issuecomment-123770179","issue_url":"https://api.github.com/repos/kaorimatz/packer-templates/issues/1","id":123770179,"user":{"login":"kaorimatz","id":1951519,"avatar_url":"https://avatars.githubusercontent.com/u/1951519?v=3","gravatar_id":"","url":"https://api.github.com/users/kaorimatz","html_url":"https://github.com/kaorimatz","followers_url":"https://api.github.com/users/kaorimatz/followers","following_url":"https://api.github.com/users/kaorimatz/following{/other_user}","gists_url":"https://api.github.com/users/kaorimatz/gists{/gist_id}","starred_url":"https://api.github.com/users/kaorimatz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/kaorimatz/subscriptions","organizations_url":"https://api.github.com/users/kaorimatz/orgs","repos_url":"https://api.github.com/users/kaorimatz/repos","events_url":"https://api.github.com/users/kaorimatz/events{/privacy}","received_events_url":"https://api.github.com/users/kaorimatz/received_events","type":"User","site_admin":false},"created_at":"2015-07-22T15:58:54Z","updated_at":"2015-07-22T15:58:54Z","body":"Thank you for reporting the issue and sorry for the inconvenience.  The cause of the kernel panic is that there is no `initrd` line in `/boot/extlinux/extlinux.conf`. grubby-8.28-11.el7 has a bug that it doesn't insert `initrd` line into extlinux.conf when installing new kernel. I think we can avoid this issue by using grub2 instead of extlinux. The following change will achieve that. \r\n\r\n```diff\r\ndiff --git a/http/centos-7.0/anaconda-ks.cfg b/http/centos-7.0/anaconda-ks.cfg\r\nindex 904a23c..d9af3bd 100644\r\n--- a/http/centos-7.0/anaconda-ks.cfg\r\n+++ b/http/centos-7.0/anaconda-ks.cfg\r\n@@ -10,7 +10,7 @@ user --name=vagrant --groups=vagrant --password=vagrant --plaintext\r\n zerombr\r\n clearpart --all --initlabel\r\n autopart --type=plain\r\n-bootloader --extlinux --timeout=1\r\n+bootloader --timeout=1\r\n\r\n %packages\r\n @core\r\n```\r\n\r\nI will commit this change after I test it on my environment."}}