{"id":722,"date":"2015-10-18T16:15:00","date_gmt":"2015-10-18T08:15:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=722"},"modified":"2023-11-04T16:28:56","modified_gmt":"2023-11-04T08:28:56","slug":"hard-disk","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/722","title":{"rendered":"Hard Disk"},"content":{"rendered":"\n

storage media<\/strong>
optical storage media
magnetic storage media<\/p>\n\n\n\n

…<\/p>\n\n\n\n

common magnetic storage media as below<\/strong>
hard disk drive: \u63a1\u8b49\u5bb9\u6613\uff0cformat\u5f8c\u9084\u6709\u8cc7\u6599
floppy disks
SSD(solid-state drive): \u63a1\u8b49\u8f03\u96e3\uff0cformat\u5f8c\u5c31\u6c92\u8cc7\u6599\u4e86
ps:
it can be wiped out by large magnet<\/p>\n\n\n\n

….<\/p>\n\n\n\n

structure of Hard Disk<\/strong>
cylinder(\u78c1\u67f1): from the tracks composed
tracks(\u78c1\u8ecc): a portion of a cylinder, Track’s ID is 0(\u5916\u5708)~1023(\u5167\u5708)
sector(\u78c1\u5340): disk block portion of a track
refer
http:\/\/www.active-undelete.com\/hdd_basic.htm<\/p>\n\n\n\n

sector<\/strong>
smallest physical storage unit on a hard drive
it is usually 512 byte
ps:
\u82e5data\u70ba700byte,\u5c31\u6703\u4f54\u75282\u500bsector
ps:
advanced format sector is 4096byte<\/p>\n\n\n\n

bad sector<\/strong>
Damaged portions of a disk<\/p>\n\n\n\n

…<\/p>\n\n\n\n

hard disk addressing<\/strong>
a method of allotting addresses to each physical block of data on a hard disk
\u4e3b\u8981\u6709\u4ee5\u4e0b\u5169\u7a2e
CHS(cylinder-head-sector):
LBA(logical block address):<\/p>\n\n\n\n

CHS:<\/strong>
\u5340\u584a\u5fc5\u9808\u4ee5\u786c\u789f\u4e0a\u67d0\u500b\u78c1\u67f1\u3001\u78c1\u982d\u3001\u78c1\u5340\u7684\u786c\u9ad4\u4f4d\u7f6e\u6240\u5408\u6210\u7684\u4f4d\u5740\u4f86\u6307\u5b9a
\u5e38\u88ab\u7528\u5728IDE device<\/p>\n\n\n\n

LBA:<\/strong>
\u5f9e0\u958b\u59cb\u7de8\u865f\u4f86\u5b9a\u4f4d\u5340\u584a\uff0c\u7b2c\u4e00sector LBA=0\uff0c\u7b2c\u4e8csector LBA=1
\u5e38\u88ab\u7528\u5728SCSI\u548cenhanced IDE device

ex:
disk capacity by CHS
22164 cylinders\/disk
80 head\/cylinder
63 sectors\/track
512 byte\/sectors
capacity=22164*80*63*512=57193758720byte
GiB for real capacity(capacity\/1024^3)=53.26GiB
GB for manufacturers(capacity\/1000^3)=57.19GB
ps
GB and GiB, GB is 1000^3 ; GiB is 1024^3
https:\/\/en.wikipedia.org\/wiki\/Gibibyte<\/p>\n\n\n\n

………………..<\/p>\n\n\n\n

ps:
common optical storage media as below<\/strong>
DVD: single-layer,4GB
HD-DVD: single-layer, 15 GB
DVD-18:15GB
Blu-Ray single-layer: 25 GB
Blu-Ray dual-layer: 50 GB
ps
preventing data is changed, recommendation using media that data only can be written once
ex:DVD+R<\/p>\n\n\n\n

ps:
Windows\u652f\u63f4\u5169\u7a2eCD ROM\u8ddfDVD\u7684\u683c\u5f0f
CDFS
UDF<\/p>\n\n\n\n

refer
https:\/\/en.wikipedia.org\/wiki\/Blu-ray
https:\/\/en.wikipedia.org\/wiki\/DVD
http:\/\/wenku.baidu.com\/view\/da7fbcd0360cba1aa811da11.html?re=view<\/p>\n","protected":false},"excerpt":{"rendered":"

storage mediaoptical storage m …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[23],"tags":[],"class_list":["post-722","post","type-post","status-publish","format-standard","hentry","category-computerarchitecture"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/722","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=722"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/722\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=722"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=722"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=722"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}