{"id":580,"date":"2012-02-20T01:33:25","date_gmt":"2012-02-20T01:33:25","guid":{"rendered":"http:\/\/www.kernelcrash.com\/blog\/?p=580"},"modified":"2012-02-20T01:33:25","modified_gmt":"2012-02-20T01:33:25","slug":"upgrading-and-downgrading","status":"publish","type":"post","link":"https:\/\/www.kernelcrash.com\/blog\/upgrading-and-downgrading\/2012\/02\/20\/","title":{"rendered":"Upgrading and Downgrading"},"content":{"rendered":"<p>I haven&#8217;t posted for a while about my Scientific Linux 6.0 setup on my Thinkpad R60. It all kind of goes well. However SL 6.0 is kind of old, 6.1 has been out for a while and 6.2 is on the horizon (UPDATE: Ooops, I see its now out!). So I thought I&#8217;d upgrade to 6.1. But before jumping into the <a href=\"www.scientificlinux.org\/documentation\/howto\/upgrade.6x\">simple update process<\/a>\u00a0I thought I&#8217;d split my root mirror as a precaution. In recent years I just keep having problems with Linux Distro updates. Its not that the update process fails, it&#8217;s usually some oddball behaviour post upgrade that I can&#8217;t live with. Anyway, I do my mdadm fail and stop to detach one half of my boot and root mirrors and do the update to 6.1.<\/p>\n<p>It all seemed to go well. I reboot &#8230; and it starts to boot but X windows does not start. I look at the Xorg log and there&#8217;s some Segmentation Fault without much detail, but I see its trying to access some dri stuff before the fault, and I know this dri stuff doesn&#8217;t exist when you have nomodeset set. See, I can&#8217;t get X to run reliably under SL 6.0 on my Thinkpad R60 without turning KMS off (I get lots of stupid flicker). Anyway, I think maybe this new kernel has fixed the flicker problem so I get rid of &#8216;nomodeset&#8217; and reboot, and sure enough X now starts and looks kind of OK.<\/p>\n<p>However leaving it on for a while the flickering starts to occur again, and then I start noticing these &#8216;kernel:Uhhuh. NMI received for unknown reason&#8217; messages on my terminal sessions periodically. The system seems to still be going OK, but I do some research and find this <a href=\"http:\/\/bugs.centos.org\/view.php?id=5369\">centos page<\/a>. So it&#8217;s not sounding like a good upgrade at this point; I can&#8217;t start X unless Kernel Mode Setting is set, and when I have Kernel Mode Setting set I can&#8217;t look at the screen because it flickers badly. Crazy!. So in less than an hour I&#8217;ve had enough pain and reverted my md mirrors back to SL 6.0.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I haven&#8217;t posted for a while about my Scientific Linux 6.0 setup on my Thinkpad R60. It all kind of goes well. However SL 6.0 is kind of old, 6.1 has been out for a while and 6.2 is on the horizon (UPDATE: Ooops, I see its now out!). So I thought I&#8217;d upgrade to [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-580","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/posts\/580","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/comments?post=580"}],"version-history":[{"count":4,"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/posts\/580\/revisions"}],"predecessor-version":[{"id":585,"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/posts\/580\/revisions\/585"}],"wp:attachment":[{"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/media?parent=580"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/categories?post=580"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kernelcrash.com\/blog\/wp-json\/wp\/v2\/tags?post=580"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}