Large Disk HOWTO Large Disk HOWTO Table of Contents Large Disk HOWTO...........................................................................................................................................1 Andries Brouwer, aeb@cwi.nl.................................................................................................................1 1. Large disks...........................................................................................................................................1 2. Units.....................................................................................................................................................1 3. Disk Access..........................................................................................................................................1 4. History of BIOS and IDE limits..........................................................................................................1 5. Booting.................................................................................................................................................1 6. Disk geometry, partitions and `overlap'...............................................................................................1 7. Translation and Disk Managers...........................................................................................................1 8. Kernel disk translation for IDE disks...................................................................................................1 9. Consequences.......................................................................................................................................2 10. Details................................................................................................................................................2 11. Clipped disks......................................................................................................................................2 12. The Linux 65535 cylinder limit.........................................................................................................2 13. Extended and logical partitions..........................................................................................................2 14. Problem solving.................................................................................................................................2 1. Large disks...........................................................................................................................................2 2. Units....................................................................................................................................................4 3. Disk Access..........................................................................................................................................4 3.1 Cylinders, heads and sectors..............................................................................................................4 3.2 Sectorsize...........................................................................................................................................5 3.3 Disksize..............................................................................................................................................5 3.4 The 1024 cylinder and 8.5 GB limits.................................................................................................5 3.5 The 137 GB limit...............................................................................................................................5 4. History of BIOS and IDE limits..........................................................................................................6 5. Booting.................................................................................................................................................7 5.1 LILO and the `lba32' and `linear' options.........................................................................................7 5.2 A LILO bug........................................................................................................................................8 5.3 1024 cylinders is not 1024 cylinders.................................................................................................8 5.4 No 1024 cylinder limit on old machines with IDE............................................................................8 5.5 Other boot loaders..............................................................................................................................8 6. Disk geometry, partitions and `overlap'..............................................................................................8 6.1 The last cylinder.................................................................................................................................9 6.2 Cylinder boundaries...........................................................................................................................9 7. Translation and Disk Managers.........................................................................................................10 8. Kernel disk translation for IDE disks.................................................................................................11 8.1 EZD..................................................................................................................................................11 8.2 DM6:DDO.......................................................................................................................................12 8.3 DM6:AUX.......................................................................................................................................12 8.4 DM6:MBR.......................................................................................................................................12 8.5 PTBL................................................................................................................................................12 8.6 Getting rid of a disk manager...........................................................................................................12 8.7 Since 2.5.70: boot parameters..........................................................................................................13 9. Consequences.....................................................................................................................................13 9.1 Computing LILO parameters...........................................................................................................14 10. Details..............................................................................................................................................15 10.1 IDE details − the seven geometries................................................................................................15 The IDENTIFY DRIVE command................................................................................................15 i Large Disk HOWTO Table of Contents Large Disk HOWTO 10.2 SCSI details....................................................................................................................................16 11. Clipped disks....................................................................................................................................18 11.1 The Linux IDE 8 GiB limit............................................................................................................18 11.2 BIOS complications.......................................................................................................................19 11.3 Jumpers that select the number of heads.......................................................................................19 11.4 Jumpers that clip total capacity......................................................................................................19 Clip to 2.1 GB.................................................................................................................................19 Clip to 33 GB.................................................................................................................................20 Maxtor.............................................................................................................................................20 IBM.................................................................................................................................................21 Seagate.............................................................................................................................................21 Maxtor D540X−4K.........................................................................................................................21 Western Digital................................................................................................................................22 11.5 READ NATIVE MAX ADDRESS / SET MAX ADDRESS.......................................................22 11.6 CONFIG_IDEDISK_STROKE.....................................................................................................23 12. The Linux 65535 cylinder limit.......................................................................................................23 12.1 IDE problems with 34+ GB disks.................................................................................................23 13. Extended and logical partitions........................................................................................................24