Large Disk mini-HOWTO ¤¤Ä¶ª©
                                       
§@ªÌ: Andries Brouwer, [1]jaeb@cwi.nl
ĶªÌ: Asd L. Chen, [2]asdchen@ms1.hinet.net

   v1.0, 26 June 1996 ½Ķ¤é´Á: 10-13 November 1997
     _________________________________________________________________
   
   ©Ò¦³¦³Ãö disk geometry ¤Î 1024 cylinder ªº­­¨î¡D
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1. °ÝÃD©Ò¦b

2. ±Ò°Ê

3. ºÏºÐ geometry ¥H¤Î¤À³Î°Ï

4. Âà´«»PºÏºÐºÞ²zµ{¦¡

5. ®Ö¤ßªº IDE ºÏºÐÂà´«

     * 5.1 EZD
     * 5.2 DM6:DDO
     * 5.3 DM6:AUX
     * 5.4 DM6:MBR
     * 5.5 PTBL
       
6. µ²½×

     * 6.1 IDE ²Ó¸`
     * 6.2 SCSI ²Ó¸`
     _________________________________________________________________
   
1. °ÝÃD©Ò¦b

   °²¦p§AªººÏºÐ¶W¹L 1024 ­ÓºÏÁL(cylinders)¡D ÁÙ¦³, °²¦p§Aªº§@·~¨t²Î¨Ï¥Î°ò
   ¥»¿é¥X¤J¨t²Î(BIOS)¡D¨º»ò§A·|¹J¨ì¤@­Ó°ÝÃD, ¦]¬°¤@¯ëºÏºÐ¿é¥X¤J¡þ¿é¤J©Ò¨Ï
   ¥Îªº INT13 BIOS ¤¶­±¥H¤@­Ó 10 ¦ì¤¸(bit) ªºÄæ¦ì¨Ó¾Þ§@ºÏÁL, ©Ò¥HµLªk¦s¨ú
   ²Ä 1024 ¤Î¤§«áªººÏÁL¡D
   
   ©¯¹Bªº¬O, Linux ¤£¨Ï¥Î BIOS, ©Ò¥H¨S¦³°ÝÃD¡D
   
   ¸Ü¬O³o»ò»¡, ¦ý¦³¨â¥ó¨Æ¨Ò¥~:
   
   (1) ·í§A¦b±Ò°Ê¨t²Î®É, Linux ÁÙ¨S¶}©l°õ¦æ©Ò¥HµLªkÅý§AÁקK³o­Ó°ÝÃD¡D³o¹ï
   LILO ¥H¤ÎÃþ¦üªº±Ò°Ê¸ü¤Jµ{¦¡(boot loaders)¦³¨Ç¼vÅT¡D
   
   (2) ¨Ï¥ÎºÏºÐªº©Ò¦³§@·~¨t²Î¥²¶·¦P·N¤À³Î°Ïªº¦ì¸m¡D´«¥y¸Ü»¡, ¦pªG§A¦b¤@Áû
   ºÏºÐ¤W¨Ï¥Î Linux ¥H¤Î, ¨Ò¦p DOS, ¨º»ò¨âªÌ¥²¶·¥H¬Û¦Pªº¤è¦¡¸ÑŪ¤À³Îªíªº¸ê
   ®Æ¡D³o¹ï Linux ®Ö¤ß¥H¤Î fdisk ¦³¨Ç¼vÅT.
   
   ©³¤U¬O¹ï©Ò¦³¬ÛÃö²Ó¸`§ó¸Ô²Óªº´y­z¡Dª`·N, §Ú¨Ï¥Î 2.0.8 ª©®Ö¤ß­ì©lµ{¦¡°µ¬°
   °Ñ¦Ò¡D¨ä¥¦ªºª©¥»¥i¯à¦³¤@ÂIÂI¥X¤J¡D
   
2. ±Ò°Ê

   ·í¨t²Î±Ò°Ê®É, BIOS ±q²Ä¤@­ÓºÏºÐ(©Î±q³nºÐ)Ū¨úºÏ°Ï 0 (¤@¯ë³qºÙªº MBR -
   Master Boot Record, ¥D±Ò°ÊºÏ°Ï)¨Ã¸õ¦Ü¦b¸Ó³Bªºµ{¦¡½X - ³q±`¬O¤@¨Ç±Ò°Ê¸ü
   ¤Jµ{¦¡(bootstrap loader)¡D ³o¨Ç¤p¤pªº±Ò°Êµ{¦¡¤@¯ë¤£·|¦³¦Û¤vªººÏºÐÅX°Êµ{
   ¦¡¦Ó·|¨Ï¥Î BIOS ©Ò´£¨ÑªºªA°È¡D³o·N¿×µÛ¥u¦³¾ã­Ó Linux ®Ö¤ß³£¦ì©ó¶}ÀYªº
   1024 ­ÓºÏÁL¤º®É¤~¯à°÷³Q±Ò°Ê¡D
   
   ³o­Ó°ÝÃD«Ü®e©ö¸Ñ¨M: ½T©w®Ö¤ß(¤]³\ÁÙ¥]¬A¨ä¥¦±Ò°Ê®É¥Î¨ìªºÀÉ®×, ¹³¬O LILO
   map ÀÉ) ¬O©ñ¦b¤@­Ó BIOS ¥i¥H¦s¨úªº¨ì, ¥þ³£¦b¶}ÀYªº 1024 ­ÓºÏÁL¤ºªº¤À³Î
   °Ï¸Ì - ³o¥i¥H(¥i¯à)¬O²Ä¤@­Ó©Î²Ä¤G­ÓºÏºÐ¡D
   
   ¥t¤@ÂI¬O±Ò°Ê¸ü¤Jµ{¦¡»P BIOS ¥²¶·¦P·N©¼¦¹¹ïºÏºÐÅÞ¿è(geometry)¤Wªº¬Ýªk¡D
   µ¹ LILO `linear' ³o­Ó¿ï¶µ°Ñ¼Æ¥i¯à·|¦³¨ÇÀ°§U¡D²Ó¸`«á­z¡D
   
3. ºÏºÐ geometry ¥H¤Î¤À³Î°Ï

   ¦pªG§AªººÏºÐ¤W¦³¦n´XºØ§@·~¨t²Î, ¨C¤@ºØ¨Ï¥Î¤@­Ó©Î¦h­Ó¤À³Î°Ï¡D¨º»ò¹ï©ó¤À
   ³Î°Ï¦ì©ó¦ó³B¤£¦Pªº¬Ýªk¥i¯à¾É­P¨aÃø©Êªº«áªG¡D
   
   MBR ¤¤¥]§t¤@­Ó¤À³Îªí´y­z¤À³Î°Ï(¥D¤À³Î°Ï: primary) ¦b¨º¸Ì¡D¦³¥|­Óªí®æµ¹
   ¥|­Ó¥D­n¤À³Î°Ï¨Ï¥Î, ¥¦­Ì¬Ý°_¨Ó¹³
   
struct partition {
        char active;    /* 0x80: bootable, 0: not bootable */
        char begin[3];  /* CHS for first sector */
        char type;
        char end[3];    /* CHS for last sector */
        int start;      /* 32 bit sector number (counting from 0) */
        int length;     /* 32 bit number of sectors */
};

   (¨ä¤¤ CHS ¬OºÏÁL¡þºÏÀY¡þºÏ°Ï: Cylinder/Head/Sector ªºÁY¼g)
   
   ¦]¦¹, ¦³¶µ¸ê°T¬O­«ÂЪº: ¤À³Î°Ïªº¦ì¸m¥i¥H¥Ñ 24 ¦ì¤¸ªº begin ¥H¤Î end Äæ
   ¦ì, ©M 32 ¦ì¤¸ªº start ¥H¤Î length Äæ¦ìµ¹©w¡D
   
   Linux ¥u¨Ï¥Î start ¥H¤Î length Äæ¦ì, ¬G³Ì¦h¥i¥H³B²z¥]§t 2^32 ­ÓºÏ°Ïªº¤À
   ³Î°Ï, ¤]´N¬O, ³Ì¤j 2 TB ªº¤À³Î°Ï¡D³o¬O²{¤µºÏºÐ¾÷ªº¨â¦Ê­¿, ©Ò¥H¤]³\¨¬°÷
   ©¹«á¤Q¦~ªº»Ý¨D¡D
   
   ¤£©¯ªº¬O, BIOS INT13 ©I¥s¨Ï¥Î¤T­Ó¦ì¤¸²Õªº CHS ½s½X, 10 ­Ó¦ì¤¸§@¬°ºÏÁL¸¹
   ½X, 8 ­Ó¦ì¤¸§@¬°ºÏÀY¸¹½X, ¤Î 6 ­Ó¦ì¤¸§@¬°ºÏ­y¤WªººÏ°Ï¸¹½X¡D ¥i¯àªººÏÁL
   ¸¹½X¬O 0-1023, ¥i¯àªººÏÀY¸¹½X¬O 0-255, ¦ÓºÏ­y¤W¥i¯àªººÏ°Ï¸¹½X¬° 1-63(¬O
   ªº, ºÏ­y¤WªººÏ°Ï¬O¥Ñ 1 °_ºâ, ¤£¬O 0)¡D ¥H³o 24 ¦ì¤¸³Ì¦h¥i¥H©w§}
   8455716864 ­Ó¦ì¤¸²Õ(7.875 GB), ³o¬O 1983 ¦~ºÏºÐ¾÷ªº¨â¦Ê­¿¡D
   
   §ó¤£©¯ªº¬O, ¼Ð·Çªº IDE ¤¶­±®e³\ 256 ­ÓºÏ°Ï¡þºÏ­y, 65536 ­ÓºÏÁL¥H¤Î 16
   ­ÓºÏÀY¡D¥¦¦Û¤v¥»¨­¥i¥H¦s¨ú 2^37 = 137438953472 ­Ó¦ì¤¸²Õ(128 GB), ¦ý¬O¥[
   ¤W BIOS ¤è­± 63 ­ÓºÏ°Ï»P 1024 ­ÓºÏÁLªº­­¨î«á¥u³Ñ 528482304 ­Ó¦ì¤¸
   ²Õ(504 MB)¥i¥H©w§}ªº¨ì¡D
   
   ³o¤£¨¬¥HÀ³¥I²{¤µªººÏºÐ, ¤H­Ì¨Ï¥Î¦UºØµwÅé©Î³nÅé¤Wªº¤èªk¨Ó§JªA¡D
   
4. Âà´«»PºÏºÐºÞ²zµ{¦¡

   ¨S¦³¤H¹ïºÏºÐªº'¯u¹ê' geometry ¦³¿³½ì¡DºÏ­yªººÏ°Ï¼Æ³q±`¬OÅܰʪº - ±µªñºÏ
   ºÐ¥~³òªººÏ­y¦³¤ñ¸û¦hªººÏ°Ï - ©Ò¥H¨S¦³'¯u¹ê'ªº¨CºÏ­yºÏ°Ï¼Æ¡D ¹ï©ó¨Ï¥ÎªÌ
   ¦Ó¨¥³Ì¦n¬O§âºÏºÐ·í§@½s¸¹ 0,1,..., ªººÏ°Ï²Õ¦X¦¨ªº½u©Ê°}¦C, Åý±±¨î¾¹¥h§ä
   ¥XºÏ°Ï¨s³º¦ì©óºÏºÐªº¨º¸Ì¡D
   
   ¦¹½u©Ê½s¸¹¤@¯ë³qºÙ¬° LBA¡D¹ï©ó geometry ¬° (C,H,S) ªººÏºÐ¦Ó¨¥ÄÝ(c,h,s)
   ªº½u©Ê¦ì§}¬° c*H*S+h*S+(s-1)¡D©Ò¦³ SCSI ±±¨î¾¹³£¨Ï¥Î LBA, ¬Y¨Ç IDE ±±¨î
   ¾¹¤]¬O¡D
   
   ¦pªG BIOS §â³o 24 ­Ó¦ì¤¸(c,h,s) Âà´«¦¨ LBA ¨ÃÁýµ¹À´±o LBA ªº±±¨î¾¹, ¨º
   »ò¤S¥i¥H©w§}¨ì 7.875 GB ¡D¨Ã¤£¨¬¥HÀ³¥I©Ò¦³ªººÏºÐ, ¦ý¤´µM¬O­Ó§ï¶i¡Dª`·N
   ¦¹³B BIOS ¨Ï¥Îªº CHS, ¥¦¤£¦A»P'¹êÅé'¦³¥ô¦óÃö«Y¡D
   
   ·í±±¨î¾¹¤£À´¦ó¬° LBA ¦ý¬O BIOS ª¾¹D¦p¦óÂà´«®É¦³¨ÇÃþ¦üªº¤èªk¥i¦æ¡D(¦b
   BIOS ³]©w¤¤³q±`ºÙ¬° 'Large'¡D)²{¦b BIOS ±N§e²{ geometry ¬°(C',H',S')µ¹
   §@·~¨t²Î, ¦Ó¦b»PºÏºÐ±±¨î¾¹·¾³q®É«h¨Ï¥Î(C,H,S)¡D ³q±` S=S', C'=C/N ¦Ó
   H'=H*N, ¨ä¤¤ N ¬O½T«O C'<=1024 ¤§ 2 ªº³Ì¤p¦¸¤è(©Ò¥H C'=C/N ®É±Ë¥hªº¼Æ®ö
   ¶O¤Ö³\®e¶q)¡D¦A¤@¦¸, ³o¤¹³\¦s¨ú³Ì¦h¹F 7.875 GB¡D
   
   ¦pªG BIOS ¤£ª¾¹D 'Large' ©Î¬O 'LBA', ¨º»òÁÙ¬O¦³³nÅ骺¸Ñ¨M¤è®×¡D¹³¬O
   OnTracker ©Î EZ-Drive ³o¨Ç­ÓºÏºÐºÞ²zµ{¦¡·|¥H¥¦­Ì¦Û¤vªº¨ç¦¡(routines)´À
   ´«±¼ BIOS ªº¡D ³q±`³o¬OÂǥѱNºÏºÐºÞ²zµ{¦¡©ñ¦b MBR ¤Î¨ä«á´X­ÓºÏ
   °Ï(OnTrack ºÙ³o¨Çµ{¦¡½X¬° DDO: Dynamic Drive Overlay )¨Ó¹F¦¨ªº, ©Ò¥H¥¦
   ·|¦b¥ô¦ó¨ä¥¦§@·~¨t²Î¤§«e³Q±Ò°Ê¡D ³o¤]´N¬O¬°¤°»ò¦b¦w¸ËºÏºÐºÞ²zµ{¦¡«á±q³n
   ºÐ±Ò°Ê¥i¯à·|¥X°ÝÃD¡D
   
   ³o¼vÅT¥i¯à¦h©ó©Î¤Ö©ó BIOS Âà´« - ¦ý¯S§O¬O¦b¬Û¦PªººÏºÐ¤W¶]¼ÆºØ¤£¦Pªº§@·~
   ¨t²Î®É, ºÏºÐºÞ²zµ{¦¡¥i¯à¤Þ°_³\¦h°ÝÃD¡D
   
   Linux ±q 1.3.14 ª©¶}©l¤ä´© OnTrack ºÏºÐºÞ²zµ{¦¡, ±q 1.3.29 ¶}©l ¤ä´©
   EZ-Drive ¡D¤U­±¦³¨Ç§ó¶i¤@¨Bªº¸ê°T¡D
   
5. ®Ö¤ßªº IDE ºÏºÐÂà´«

   ¦pªG Linux °»´ú¨ì IDE ºÏºÐ¤W¦³¬Y¨ÇºÏºÐºÞ²zµ{¦¡¦s¦b, ¥¦±N·|¸ÕµÛ¨Ï¥Î»P¸Ó
   ºÏºÐºÞ²zµ{¦¡¬Û¦Pªº¤è¦¡¨Ó­«·s¹ïÀ³ºÏºÐ, ©Ò¥H Linux ¬Ý¨ì»P, ¨Ò¦p DOS °t¦X
   OnTrack ©Î¬O EZ-Drive ¬Û¦PªººÏºÐ¤À³Î¡D µM¦Ó, ·í§A¦b«ü¥O¦C¤W«ü©w
   geometry ®É, ´N¤£·|°µ¥ô¦óªº­«·s¹ïÀ³ - ©Ò¥H¤@¦æ `hd=cyls,heads,secs' «ü
   ¥O¦C¿ï¶µ¥i¯à¨ú®ø±¼»PºÏºÐºÞ²zµ{¦¡ªº¬Û®e¡D
   
   ¦¹­«·s¹ïÀ³ªº¤è¦¡¬O¹Á¸Õ 4,8,16,32,64,128,255 ºÏÀY¼Æ(H*C «O«ù¤£ÅÜ)ª½¨ì C
   <= 1024 ©Î¬O H = 255¡D
   
   ²Ó¸`¦p¤U - ¤p¸`ªº©ïÀY¬O¥X²{¦b¬Û¹ïÀ³¤§±Ò°Ê°T®§¸Ìªº¦r¦ê¡D¦b¦¹¥H¤Î¦b³o¥÷¤å
   ¥ó¥ô¦ó¨ä¥¦¦a¤è¤¤¤À³Îªº«¬ºA³£¥H¤Q¤»¶i¦ì¼Æ¦rªí¥Ü¡D
   
5.1 EZD

   °»´ú¨ì EZ-Drive , ¦]¬°²Ä¤@­Ó¥D­n¤À³Î°Ï«¬ºA¬° 55 ¡D¦p¤W­z­«·s¹ïÀ³
   geometry, ¥B©¿²¤±q²Ä 0 ºÏ°ÏŪ¤Jªº¤À³Îªí - ¥H²Ä 1 ºÏ°Ïªº¤À³Îªí¨ú¥N¡DºÏºÐ
   ªº°Ï¶ô¸¹½X(block numbers) ¨S¦³§ïÅÜ, ¦ý¹ïºÏ°Ï 0 ªº¼g¤J·|Âà¦VºÏ°Ï 1¡D¦¹°Ê
   §@¥i¥HÂǥѭקï¦b ide.c ¤¤ªº
   
     #define FAKE_FDISK_FOR_EZDRIVE 0
     
   ¨Ã­«·s½sĶ®Ö¤ß¨Ó§ïÅÜ¡D
   
5.2 DM6:DDO

   °»´ú¨ì OnTrack DiskManager(¦b²Ä¤@­ÓºÏºÐ¤W), ¦]¬°²Ä¤@­Ó¥D­n¤À³Î°Ï«¬ºA¬°
   54 ¡D¦p¤W­z­«·s¹ïÀ³ geometry ¦Ó¥B¾ã­ÓºÏºÐ¥­²¾ 63 ­ÓºÏ°Ï¡D (©Ò¥HªººÏ°Ï
   63 Åܦ¨ºÏ°Ï 0)µM«á±q·sªº²Ä 0 ºÏ°ÏŪ¤J·sªº MBR (»P¤À³Îªí)¡D¦¹¥­²¾·íµM¬O
   ¬° DDO ¯dªÅ¶¡ - ³o¤]´N¬O¬°¤°»ò¨ä¥¦ºÏºÐ¤£¥²¥­²¾¡D
   
5.3 DM6:AUX

   °»´ú¨ì OnTrack DiskManager(¦b¨ä¥¦ºÏºÐ¤W), ¦]¬°²Ä¤@­Ó¥D­n¤À³Î°Ï«¬ºA¬°
   51 ©Î 53¡D¦p¤W­z­«·s¹ïÀ³ geometry ¡D
   
5.4 DM6:MBR

   °»´ú¨ì¬Yª©ªº OnTrack DiskManager, ¨Ã«DÂǥѤÀ³Î°Ï«¬ºA, ¦Ó¬Oñ
   ¦W(signature)¡D(´ú¸Õ¦b MBR ¸Ì²Ä 2,3 ¦ì¤¸²Õªº°¾²¾­È¬O§_¤£¤j©ó 430, ¦Ó¥B
   ¦b¦¹°¾²¾¦ì§}§ä¨ìªº short µ¥©ó 0x55AA, «á­±¨Ã¸òµÛ¤@­Ó©_¼Æªº¦ì¤¸²Õ) ¦A¤@
   ¦¸¦p¤W­z­«·s¹ïÀ³ geometry ¡D
   
5.5 PTBL

   ³Ì«á, ®Ö¤ß·|¹Á¸Õ±q¥D¤À³Î°Ïªº start ¥H¤Î end ­È±ÀÂ_Âà´«¤è¦¡: ­Y¬Y¨Ç¤À³Î
   °Ïªº start ¥H¤Î end ºÏÁL¤p©ó 256, ¦Ó¥B start ¥H¤Î end ºÏ°Ï¸¹½X¤À§O¬° 1
   ©M 63 , ¦Ó¥B end ºÏÀY¬° 31, 63, ©Î 127, ¨º»ò, ¦]¬°¨ÌºD¨Ò¤À³Î°Ï·|¦bºÏÁL
   Ãä¬Éµ²§ô, ¦Ó¥B§ó¦]¬° IDE ¤¶­±³Ì¦h¨Ï¥Î 16 ­ÓºÏÀY, ¬G±À´ú¦³¶}±Ò BIOS Âà
   ´«, ¤À§O¨Ï¥Î 32, 64 ©Î 128 ºÏÀY¼Æ­«·s¹ïÀ³ geometry¡D (¤]³\³o¸Ì¦³ÂI·å
   ²«, genhd.c ¤£À³¸Ó´ú¸ÕºÏÁL¸¹½X«e¨â­Ó¦ì¤¸¶Ü?)µL½×¦p¦ó, ·í¥Ø«eªº
   geometry ¤w¸g¬°¨CºÏ­y 63 ­ÓºÏ°Ï¥B¦Ü¤Ö³o»ò¦hºÏÀY®É, ¤£·|°µ­«·s¹ïÀ³ (¦]¬°
   ³o¥i¯à·N¿×µÛ­«¹ïÀ³¤w§¹¦¨)¡D
   
6. µ²½×

   ³o¨ì©³·N¿×µÛ¤°»ò? ¹ï Linux ªº¨Ï¥ÎªÌ¦Ó¨¥¥u¦³¤@¥ó¨Æ: ´N¬O¥L­Ì¥²¶·±o½T«O
   LILO ¥H¤Î fdisk ¨Ï¥Î¥¿½Tªº geometry , ¨ä¤¤'¥¿½T'ªº©w¸q¹ï fdisk ¦Ó¨¥¬O»P
   ¨ä¥¦¦b¦P¤@­ÓºÏºÐ¤Wªº§@·~¨t²Î©Ò¨Ï¥Îªº geometry ¬Û¦P, ¦Ó¹ï LILO ¦Ó¨¥¬O¯à
   °÷¦b±Ò°Ê®É´Á¦¨¥\¦a»P BIOS ¥æ½Íªº geometry¡D(³o¨âªÌ³q±`¬Û²Å¡D)
   
   fdisk ¦p¦ó±oª¾¸Ó geometry ? ¥¦¸ß°Ý®Ö¤ß, ¨Ï¥Î HDIO_GETGEO ioctl¡D¦ý¨Ï¥Î
   ªÌ¥i¥H¥æ½Í¦¡¦a©Î¦b«ü¥O¦C¤W­«©w geometry¡D
   
   LILO ¦p¦ó±oª¾¸Ó geometry ? ¥¦¸ß°Ý®Ö¤ß, ¨Ï¥Î HDIO_GETGEO ioctl¡D ¦ý¨Ï¥Î
   ªÌ¥i¥H¥Î `disk=' ¿ï¶µ­«©w¡D¤]¥i¥Hµ¹ LILO ¤@­Ó linear ¿ï¶µ, ¦p¦¹¥¦±N¦b¨ä
   map Àɤ¤Àx¦s LBA ¦ì§}¥H¨ú¥N CHS ¦ì§}, ¨Ã¥B¦b±Ò°Ê®É´Á§ä¥X¸Ó geometry ¨Ó
   ¨Ï¥Î(ÂÇ¥Ñ INT 13 ¥\¯à©I¥s 8 ¨Ó¸ß°ÝºÏºÐªº geometry)¡D
   
   ®Ö¤ß¦p¦óª¾¹D¸Ó«ç»ò¦^µª? ­º¥ý, ¨Ï¥ÎªÌ¥i¯à¥H `hd=cyls,heads,secs' «ü¥O¦C
   ¿ï¶µ©ú½T¦a«ü©w geometry, §_«h®Ö¤ß±N¸ß°ÝµwÅé¡D
   
6.1 IDE ²Ó¸`

   Åý§Ú¸Ô²Ó»¡©ú¡DIDE ÅX°Êµ{¦¡¦³¥|­ÓÃö©ó geometry ªº¸ê°T¨Ó·½¡D²Ä¤@
   ­Ó(G_user)¬O¨Ï¥ÎªÌ¦b«ü¥O¦C¤W©Ò«ü©wªº¡D ²Ä¤G­Ó(G_bios)¬O BIOS ªº©T©wºÏºÐ
   °Ñ¼Æªí(¥u¥Î©ó²Ä¤@¤Î²Ä¤G­ÓºÏºÐ), ¦b¨t²Î±Ò°Ê®É, ¤Á´«¦Ü 32 ¦ì¤¸¼Ò¦¡¤§«eŪ
   ¤J¡D ²Ä¤T­Ó(G_phys)¤Î²Ä¥|­Ó(G_log) ¬O¥Ñ IDE ±±¨î¾¹¶Ç¦^, §@¬°¹ï
   IDENTIFY «ü¥Oªº¦^À³ - ¥¦­Ì¬O '¹êÅ骺' ¥H¤Î '¥Ø«eÅÞ¿è¤Wªº' geometries¡D
   
   ¥t¤@¤è­±, ¹ï©ó geometry ÅX°Êµ{¦¡»Ý­n¨â­Ó­È: ¨ä¤¤¤§¤@¬O G_fdisk, ¥Ñ
   HDIO_GETGEO ioctl ¶Ç¦^, ¥t¤@­Ó¬O G_used , ³o¬O°õ¦æ¿é¥X¡þ¤J®É¹ê»Ú¨Ï¥Îªº
   ¡D ¦pªGµ¹©w G_user «h G-fdisk ¥H¤Î G_used ¨âªÌ³£·|³]¬° G_user, ·í¦¹¸ê°T
   ¬O®Ú¾Ú CMOS ©Ò´£¨Ñ®É«h³]¬° G_bios , ¨ä¥¦±¡§Î³]¬° G_phys¡D¦pªG G_log ¬Ý
   °_¨Ó¦X²z«h G_used ´N³]¬° G_log¡D ¤£µM, ¦pªG G_used ¤£¦X²z¦Ó G_phys ¬Ý°_
   ¨Ó¦X²z¨º»ò G_used ´N³]¬° G_phys¡D¦¹³Bªº'¦X²z'¥NªíºÏÀY¼Æ¦b 1-16 ªº½d³ò¤º
   ¡D
   
   ´«­Ó¤è¦¡»¡: «ü¥O¦C¿ï¶µ¤j©ó BIOS , ¨Ã¥B¨M©w fdisk ¬Ý¨ìªº¼Ë¤l, ¦ý¦pªG¥¦«ü
   ©wÂà´«ªº geometry(ºÏÀY¼Æ¤j©ó 16), «h®Ö¤ß·|ÂÇ¥Ñ IDENTIFY «ü¥Oªº¿é¥X­«©w
   ¥¦¡D
   
6.2 SCSI ²Ó¸`

   ¦b SCSI ¤è­±±¡ªp¦³¤@ÂIÂI¤£¦P, ¦]¬° SCSI «ü¥O¤w¸g¨Ï¥ÎÅÞ¿è°Ï¶ô¸¹½X, ©Ò¥H
   'geometry' ¹ï¹ê»Úªº¿é¥X¡þ¤J§¹¥þ¨SÃö«Y¡D µM¦Ó, ¤À³Î°Ïªº®æ¦¡¤´µM¬O¬Û¦P
   ªº, ©Ò¥H fdisk ¥²¶·±o®º³y¨Ç geometry , ¨Ã¥B¤]¦b¦¹¨Ï¥Î HDIO_GETGEO - ¯u
   ªº, fdisk ¤£·|¤À¿ë IDE ¥H¤Î SCSI ºÏºÐ¡D §A¥i¥H±q¤U­±ªº¸Ô²Ó´y­z¨£¨ì¦UºØ
   ÅX°Êµ{¦¡®º³y¤@¨Ç­Ó¤£¦Pªº geometry ¡D¯u¬O, ¤@¹Î²V¶Ã¡D
   
   ¦pªG§A¨S¦³¨Ï¥Î DOS ©Î³oÃþ¨t²Î, ¨º»òÁקK¨Ï¥Î©Ò¦³ÃB¥~ªºÂà´«³]©w, ¥i¯àªº
   ¸Ü, ¾¨ºÞ¨Ï¥Î 64 ºÏÀY, ¨CºÏ­y 32 ºÏ°Ï (¨}¦nªº, ¤è«K¨CºÏÁL 1 MB), ¦p¦¹·í
   §A§âºÏºÐ±q¤@­Ó±±¨î¾¹´«¨ì¥t¤@­Ó¥h®É¤£·|¹J¨ì¥ô¦ó°ÝÃD¡D ¬Y¨Ç SCSI ºÏºÐÅX°Ê
   µ{¦¡ (aha152x,pas16,ppa,qlogicfas,qlogicisp)«D±`¦b·N»P DOS ªº¬Û®e©Ê¦Ó¤£
   ¤¹³\¥u¦³ Linux ªº¨t²Î¨Ï¥Î¶W¹L 8 GB ªº®e¶q, ³o¬O°¦¯äÂΡD
   
   ¯u¹êªº geometry ¬O¤°»ò? ³Ì²³æªºµª®×¬O¨S¦³³oºØªF¦è¡D¦pªG¯u¦³ªº¸Ü, §A¤£
   ·|·Qª¾¹D, ¦Ó¥Bªºªº½T½T±q¤£, ¥Ã¤£»Ý§i¶D fdisk ©Î¬O LILO ©Î®Ö¤ß¦³Ãö¥¦ªº¨Æ
   ¡D³oµ´¹ï¬O SCSI ±±¨î¾¹»PºÏºÐ¤§¶¡ªº¨Æ¡D Åý§Ú­«Âгo¥y¸Ü: ¥u¦³Äø³J·|§i¶D
   fdisk/LILO/Kernel SCSI ºÏºÐ¯u¹êªº geometry ¡D
   
   ¦ý¦pªG§A¦n¾Ç¥B°í«ù, ¥i¥H°ÝºÏºÐ¾÷¦Û¤v¡D¦³­Ó­«­n«ü¥O READ CAPACITY ±N·|¶Ç
   ¦^ºÏºÐªºÁ`®e¶q, ¦Ó¥B¦³­Ó MODE SENSE «ü¥O Rigid Disk Drive Page(page
   04) ·|¶Ç¦^ºÏÁL¥H¤ÎºÏÀYªº¼Æ¥Ø(³o¬O¤£¯à§ïÅܪº¸ê°T), ¦Ó¦b Format
   Page(page 03)¦³¨CºÏ°Ïªº¦ì¤¸²Õ, ¥H¤Î¨CºÏ­yªººÏ°Ï¼Æ¡D ³o¼Æ¦r¤@¯ë»P notch
   ¦³Ãö, ¦Ó¥B¨CºÏ­yªººÏ°Ï¼Æ¬OÅܰʪº - ¥~³òªººÏ­y¾Ö¦³¤ñ¤º°éºÏ­y¦hªººÏ°Ï
   ¡DLinux µ{¦¡ scsiinfo ·|µ¹¤©³o¶µ¸ê°T¡D ¨ä¤¤¦³³\¦hÁcº¾ªº²Ó¸`, ¦Ó¥B«Ü©ú¥Õ
   ªº, ¨S¦³¤H(¤]³\¬Æ¦Ü¬O§@·~¨t²Î)»Ý­n¨Ï¥Î³o¶µ¸ê°T¡D ÁÙ¦³, ¦]¬°§Ú­Ì¥uÃö¤ß
   fdisk ¥H¤Î LILO , ¤@¯ë±o¨ìªº¦^µª¹³ C/H/S=4476/27/171 - ³o¼Ëªº­È fdisk
   ®Ú¥»¤£¯à¨Ï¥Î, ¦]¬°¤À³Îªí¥u«O¯d 10resp. 8resp. 6 bits µ¹ C/H/S¡D
   
   ¨º®Ö¤ß¤§ HDIO_GETGEO ±q¦ó³B¨ú±o¨ä¸ê°T? ¶â, ¤£¬O±q SCSI ±±¨î¾¹, ´N¬O±À½×
   ²q´ú¡D ¦³¨ÇÅX°Êµ{¦¡¦ü¥G»{¬°§Ú­Ì·Qª¾¹D '¯u¬Û' , ¦ý§Ú­Ì·íµM¥u·Qª¾¹D DOS
   ©Î OS/2 FDISK (©Î Adaptec AFDISK µ¥µ¥)©Ò¥Îªº¡D
   
   ª`·N, Linux fdisk »Ý­nºÏÀY¼Æ H ¥H¤Î¨CºÏ­yºÏ°Ï¼Æ S ¥H«KÂà´« LBA ºÏ°Ï¸¹½X
   ¦¨¬° c/h/s ¦ì§}, ¦ýºÏÁL¼Æ C ¦b¦¹Âà´«¤¤¨Ã¥¼§êºt¤°»ò¨¤¦â¡D ¦³¨ÇÅX°Êµ{¦¡¨Ï
   ¥Î (C,H,S) = (1023,255,63) ¨Óªí¥ÜºÏºÐ®e¶q¦Ü¤Ö¬° 1023*255*63 ­ÓºÏ°Ï¡D³o
   ¬O¤£©¯ªº, ¦]¬°³o¤£¯àÅã¥Ü¹ê»Úªº¤j¤p, ¦Ó¥B±N­­¨î¤j³¡¥÷ª©¥»¤§ fdisk ªº¨Ï¥Î
   ªÌ¨äºÏºÐ³Ì¤j¨ì 8 GB - ²{¤µ¹ê»Úªº­­¨î¡D
   
   ¦b¤U­±ªº´y­z¤¤, M ªí¥ÜºÏºÐªº¥þ³¡®e¶q, ¦Ó C,H,S ¬OºÏÁL, ºÏÀY¥H¤Î¨CºÏ­yºÏ
   °Ï¼Æ¡D¦pªG§Ú­Ì§â C ·í§@ M/(H*S) ¨ºµ¹ H,S ´N¥i¥Hº¡¨¬¡D
   
   ¨Ì¹w³], H=64, S=32.
   
   aha1740, dtc, g_NCR5380, t128, wd7000:
          H=64, S=32.
          
   aha152x, pas16, ppa, qlogicfas, qlogicisp:
          H=64, S=32 °£«D C > 1024, ¦¹±¡ªp¤U H=255, S=63, C = min(1023,
          M/(H*S)). (¬G C ³QºIÂ_, ¥B H*S*C ¤£¬OºÏºÐ®e¶qªºªñ¦ü­È. ³o±N·|²V
          ·n²c¤j³¡¥÷ª©¥»ªº fdisk.) ppa.c µ{¦¡½X¨Ï¥Î M+1 ¨ú¥N M ¨Ã»{¬°³o¬O
          ¦]¬°¦b sd.c ¸Ìªº¤@°¦¯äÂÎ¨Ï M ªº­È¤Ö¤@¡D
          
   advansys:
          H=64, S=32 °£«D C > 1024 ¦Ó¥BÁÙ¶}±Ò BIOS ¤¤ªº `> 1 GB' ¿ï¶µ, ¦¹
          ±¡ªp¤U H=255, S=63.
          
   aha1542:
          ¸ß°Ý±±¨î¾¹¨Ï¥Î¨âºØ¥i¯àªº schemes ¤¤ªº¨º¤@ºØ, ¨Ã¥B¨Ï¥Î H=255,
          S=63 ©Î H=64, S=32. «eªÌ¦³­Ó±Ò°Ê°T®§ "aha1542.c: Using extended
          bios translation".
          
   aic7xxx:
          H=64, S=32 °£«D C > 1024, ¦Ó¥BÁÙµ¹¤F "extended" ±Ò°Ê°Ñ¼Æ, ©Î¦b
          SEEPROM ©Î BIOS ³]¤F `extended' ¦ì¤¸, ¦¹±¡ªp¤U H=255, S=63.
          
   buslogic:
          H=64, S=32 °£«D C >= 1024, ¦Ó¥BÁٱҰʱ±¨î¾¹ªºÂX¥RÂà´«, ¦¹±¡ªp¤U
          ­Y M < 2^22 «h H=128, S=32; §_«h H=255, S=63. µM¦Ó, ¿ï¾Ü
          (C,H,S) ¤§«á, Ū¤J¤À³Îªí, ­Y¤TºØ¥i¯àªº (H,S) = (64,32),
          (128,32), (255,63) ¤¤ endH=H-1 ªº­È¬Ý¨Ó¥i¦æ«h¨Ï¥Î¸Ó¹ï (H,S) , ¨Ã
          ¦L¥X±Ò°Ê°T®§ "Adopting Geometry from Partition Table".
          
   fdomain:
          ±q BIOS Drive Parameter Table §ä¥X geometry ¸ê°T, ©Î±q¤À³ÎªíŪ¨ú
          ¨Ã¨Ï¥Î H=endH+1, S=endS µ¹²Ä¤@­Ó¤À³Î°Ï, ­Y«DªÅ, ©Î¨Ï¥Î H=64,
          S=32 for M < 2^21 (1 GB), H=128, S=63 for M < 63*2^17 (3.9 GB)
          and H=255, S=63 otherwise.
          
   in2000:
          ¨Ï¥Î (H,S) = (64,32), (64,63), (128,63), (255,63) ¤¤²Ä¤@­ÓÅý C
          <= 1024 ªº. ¦¹±¡ªp¤U, ¦b 1023 ºI±¼ C .
          
   seagate:
          ±qºÏºÐŪ¨ú C,H,S. (¯u¸Û¹ê!) ¦pªG C ©Î S ¤Ó¤j, ©ñ¤J S=17, H=2 ¨Ã
          ­¿¼W H ª½¨ì C <= 1024. ³oªí¥Ü H ±N¬° 0 ¦pªG M > 128*1024*17
          (1.1 GB). ³o¬O°¦¯äÂÎ.
          
   ultrastor and u14_34f:
          ¤TºØ¹ïÀ³¤§¤@ ((H,S) = (16,63), (64,32), (64,63)) ®Ú¾Ú±±¨î¾¹ªº¹ï
          À³¼Ò¦¡¦Ó©w.
          
   ¦pªGÅX°Êµ{¦¡¨S¦³«ü©w geometry , §Ú­Ì´N¦^¨ì¨Ï¥Î¤À³Îªí©ÎºÏºÐÁ`®e¶q¨Ó±ÀÂ_
   ²q´ú¡D
   
   ¥J²Ó¬Ý¬Ý¤À³Îªí¡D¦]¬°¨ÌºD¨Ò¤À³Î°Ï¦bºÏÁLÃä¬Éµ²§ô, §Ú­Ì¥i¥H¬°¥ô¦ó¤À³Î°Ï©w
   end=(endC,endH,ednS) , ¥u­n©ñ¤J H = endH+1 ¤Î S = endS¡D (°O±oºÏ°Ï¥Ñ 1
   °_ºâ¡D)§ó©ú½T¦aªº»¡¡D¦pªG¦³­Ó¤£¬OªÅªº¤À³Î°Ï, «h¥H³Ì¤jªº beginC ­p¡D ¹ï
   ©ó¦¹¤À³Î°Ï, ¬Ý¬Ý end+1, ­pºâ¥[¤W start ¥H¤Î length ¨Ã¥B°²³]¦¹¤À³Î°Ï¦b¬Y
   ºÏÁLÃä¬Éµ²§ô¡D ¦pªG¨â­Ó­È³£¬Û²Å, ©Î endC = 1023 ¥B start+length ¬O
   (endH+1)*endS ªº­¿¼Æ, ¨º»ò°²©w¦¹¤À³Î°Ï¯uªº¬O¦bºÏÁLÃä¬É, ¨Ã©ñ¤J H =
   endH+1 ¥H¤Î S = endS¡D ¦pªG¤£¹ï, ¤£¬O¦]¬°¨S¦³¤À³Î°Ï, ´N¬O¦]¬°¥¦­Ìªº¤j¤p
   «Ü©_©Ç, ¨º»ò¥u¬ÝºÏºÐ®e¶q M¡D ºtºâªk: ©ñ¤J H = M/(62*1024)(µL±ø¥ó¶i
   ¦ì),S = M/(1024*H)(µL±ø¥ó¶i¦ì), C = M/(H*S)(µL±ø¥ó±Ë¥h)¡D³o¯à²£¥Í¤@
   (C,H,S) ¨ä¤¤ C ³Ì¤j 1024 ¦Ó S ³Ì¤j 62¡D

References

   1. mailto:aeb@cwi.nl
   2. mailto:asdchen@ms1.hinet.net