{"id":199,"date":"2013-01-01T02:43:55","date_gmt":"2013-01-01T09:43:55","guid":{"rendered":"http:\/\/www.zokul.com\/zokulblog\/?p=199"},"modified":"2014-11-29T22:33:22","modified_gmt":"2014-11-30T05:33:22","slug":"disk-access","status":"publish","type":"post","link":"http:\/\/www.zokul.com\/zokulblog\/?p=199","title":{"rendered":"disk access"},"content":{"rendered":"<p>this is for old fashioned mechanical harddisks obviously, they will be around for quite some time<\/p>\n<p>when reading a fragmented disk you should first get all the positions of the data, and then sort by cylinder number, then start reading from the outside inwards w\/o searching, just track-to-track operations since those are done within a milisecond<\/p>\n<p>the disks should not be idle &#8211; they have to be either read, fill a cache, write,\u00a0search sector\/cylinder, defrag, encrypt, compress etc<\/p>\n<p>it&#8217;s OK to read\/write out-of-band sectors when it&#8217;s faster to do so<\/p>\n<p>why can&#8217;t a disk controller compress data? or defrag data? or de-dupe data?<br \/>\nit&#8217;s slower than the host, but\u00a0they got all day, and unless it&#8217;s a busy server they are idle most of the time, and have now 64+ Mbyte cache, and must handle 1 Gbit\/s and more throughput, so there seems to be some processing capacity<\/p>\n","protected":false},"excerpt":{"rendered":"<p>this is for old fashioned mechanical harddisks obviously, they will be around for quite some time when reading a fragmented disk you should first get all the positions of the data, and then sort by cylinder number, then start reading from the outside inwards w\/o searching, just track-to-track operations since those are done within a [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,8],"tags":[],"class_list":["post-199","post","type-post","status-publish","format-standard","hentry","category-hardware-stuff","category-software-stuff"],"_links":{"self":[{"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=\/wp\/v2\/posts\/199","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=199"}],"version-history":[{"count":6,"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=\/wp\/v2\/posts\/199\/revisions"}],"predecessor-version":[{"id":259,"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=\/wp\/v2\/posts\/199\/revisions\/259"}],"wp:attachment":[{"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=199"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=199"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.zokul.com\/zokulblog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=199"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}