{"id":7460,"date":"2014-06-19T03:59:30","date_gmt":"2014-06-19T03:59:30","guid":{"rendered":"https:\/\/unknownerror.org\/index.php\/2014\/06\/19\/kvm-image-jammed-after-power-unplug-collection-of-common-programming-errors\/"},"modified":"2014-06-19T03:59:30","modified_gmt":"2014-06-19T03:59:30","slug":"kvm-image-jammed-after-power-unplug-collection-of-common-programming-errors","status":"publish","type":"post","link":"https:\/\/unknownerror.org\/index.php\/2014\/06\/19\/kvm-image-jammed-after-power-unplug-collection-of-common-programming-errors\/","title":{"rendered":"KVM Image Jammed After Power Unplug-Collection of common programming errors"},"content":{"rendered":"<ul>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/fc8d674edce4942290eae0960966bef2?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nMKT<\/p>\n<p>We have a HP DL380 Server which has ubuntu 12.04 OS as Host and for Virtualization KVM. Power of our server unplugged suddenly and after plugging power size of image of vm in<\/p>\n<pre><code>*\/var\/lib\/libvirt\/images\/image.img*\n<\/code><\/pre>\n<p>decreased from 100G to 1G and when vm power up following error occurred:<\/p>\n<p>error: unknown filesystem grub rescue&gt;<\/p>\n<p>we had critical data on vm so what should we do ?<\/p>\n<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/5386edb95ebf906d70f0fe1e5fe1005e?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nHopelessN00b<\/p>\n<p>So, you put &#8220;critical data&#8221; on a server with no backups (and from the sounds of things), no battery or NVRAM-backed write cache, and no UPS?<\/p>\n<p>You might, maybe, be able to get some professional data recovery help and pay thousands of dollars to have that critical data back in a few weeks, but in the general case:<\/p>\n<p>You&#8217;re screwed. The only thing you can do is learn a lesson (or two) from this. To wit.<\/p>\n<ol>\n<li>\n<p>Data you don&#8217;t backup is data you don&#8217;t care about. If you have data you care about, you back it up.<\/p>\n<\/li>\n<li>\n<p>Power matters. Plug your servers into UPS(es), employ battery or flash-backed write caches, and control physical access to your servers and their power sources.<\/p>\n<\/li>\n<li>\n<p>An ounce of prevention is worth a pound of cure. The prevention route&#8217;s cheaper too.<\/p>\n<\/li>\n<\/ol>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>MKT We have a HP DL380 Server which has ubuntu 12.04 OS as Host and for Virtualization KVM. Power of our server unplugged suddenly and after plugging power size of image of vm in *\/var\/lib\/libvirt\/images\/image.img* decreased from 100G to 1G and when vm power up following error occurred: error: unknown filesystem grub rescue&gt; we had [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-7460","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/7460","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/comments?post=7460"}],"version-history":[{"count":0,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/7460\/revisions"}],"wp:attachment":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/media?parent=7460"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/categories?post=7460"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/tags?post=7460"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}