{"id":847,"date":"2012-01-05T22:56:49","date_gmt":"2012-01-06T03:56:49","guid":{"rendered":"http:\/\/pappp.net\/?p=847"},"modified":"2012-01-05T22:57:27","modified_gmt":"2012-01-06T03:57:27","slug":"warewulf-and-the-kernel-documentation","status":"publish","type":"post","link":"https:\/\/pappp.net\/?p=847","title":{"rendered":"Warewulf, and the Kernel Documentation"},"content":{"rendered":"<p>Earlier, while trying to instrument a failing boot from some peculiar nodes we were trying to provision, I came across the following gem in the Linux kernel documentation, from <a href=\"http:\/\/www.kernel.org\/doc\/Documentation\/filesystems\/ramfs-rootfs-initramfs.txt\">Documentation\/filesystems\/ramfs-rootfs-initramfs.txt<\/a>:<\/p>\n<blockquote><p>\nNote: The cpio man page contains some bad advice that will break your initramfs archive if you follow it.  It says &#8220;A typical way to generate the list of filenames is with the find command; you should give find the -depth option to minimize problems with permissions on directories that are unwritable or not searchable.&#8221;  Don&#8217;t do this when creating initramfs.cpio.gz images, it won&#8217;t work.  The Linux kernel cpio extractor won&#8217;t create files in a directory that doesn&#8217;t exist, so the directory entries must go before the files that go in those directories.  The above script gets them in the right order.\n<\/p><\/blockquote>\n<p>Yup.  If you follow the documentation for the tool, it renders your system unbootable.  The linked documentation is actually pretty cool &#8211; it explains the rationale for the current state of the boot process, including that charming behavior, and links to the original discussions.  But the particular behavior is still kind of psychotic. <\/p>\n<p><strong>Upside:<\/strong> After today&#8217;s digging I know all kinds of neat things about the current Linux boot process, which I hadn&#8217;t relearned after it changed at the the 2.4\/2.6 transition.  Similarly, the last couple times we had problems with <a href=\"http:\/\/warewulf.lbl.gov\/trac\/\">Warewulf 3<\/a> (or, actually, Redhat-isims interfering with Warewulf) brought me back up to speed on interpreting raw packet logs from <a href=\"http:\/\/www.wireshark.org\/\">Wireshark<\/a>, so this has all been thoroughly educational.<br \/>\n<strong>Downside:<\/strong> I have even less idea why the nodes won&#8217;t finish booting &#8211; the check I was adding was to test our theory that they were running out of memory, and they don&#8217;t seem to be.  <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Earlier, while trying to instrument a failing boot from some peculiar nodes we were trying to provision, I came across the following gem in the Linux kernel documentation, from Documentation\/filesystems\/ramfs-rootfs-initramfs.txt: Note: The cpio man page contains some bad advice that &hellip; <a href=\"https:\/\/pappp.net\/?p=847\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,8,1,3],"tags":[51,186],"class_list":["post-847","post","type-post","status-publish","format-standard","hentry","category-computers","category-diy","category-general","category-school","tag-linux","tag-warewulf"],"_links":{"self":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts\/847","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=847"}],"version-history":[{"count":0,"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts\/847\/revisions"}],"wp:attachment":[{"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=847"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=847"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=847"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}