Adding hard disks

Changing default disk parameters using dkinit

dkinit allows you to display, modify, or select default disk parameters if you are installing an unusual or nonstandard disk.

If you have a standard hard disk (one that is supported by your computer hardware or special motherboard ROM), select the default disk configuration and quit. The installation continues by running fdisk(ADM) to allow you to partition the disk. See ``Partitioning a hard disk using fdisk''.

NOTE: If you are not sure whether your disk is nonstandard, check the default parameters using the dkinit display option. Calculate the size of your disk in bytes using the formula:

size = cylinders x heads x sectors per track x 512

Some drives are sold by formatted size, others by unformatted size. The formatted size of a drive is approximately 85% of its unformatted size. The parameters displayed by dkinit may not match the drive manufacturer's documentation. Some controllers have optional translation, mapping, or 63-sector modes. If one of these modes was chosen during low-level formatting, your SCO OpenServer system must be initialized with the translated parameters and not those of the physical drive. In all cases, the known size of the drive should approximately match the size calculated above from the disk parameters.

If your disk is nonstandard, you must enter information to replace the disk configuration information in ROM. If you are unsure of what parameters to enter for your nonstandard disk, contact your disk manufacturer for this information.

You will need to supply the following information:

Disk parameter Description

cylinders number of cylinders on the entire disk

heads number of disk read/write heads

write reduce starting cylinder for reducing the current to the disk head when writing to inner cylinders

write precomp starting cylinder for adjusting the spacing of certain bit sequences when writing to inner cylinders

ecc number of bits of error correction on I/O transfers

control controller type number

landing zone cylinder where heads are parked

sectors/track number of sectors per track

Disk parameter	Description
cylinders	number of cylinders on the entire disk
heads	number of disk read/write heads
write reduce	starting cylinder for reducing the current to the disk head when writing to inner cylinders
write precomp	starting cylinder for adjusting the spacing of certain bit sequences when writing to inner cylinders
ecc	number of bits of error correction on I/O transfers
control	controller type number
landing zone	cylinder where heads are parked
sectors/track	number of sectors per track

NOTE: Most IDE, EIDE, and UDMA disk drives have integrated disk controllers that handle write-current reduction and write-precompensation automatically. If this is the case, enter 0 for these values.

Quit dkinit to save the disk parameters you have changed.

``Hard disk geometry and terminology'' shows the internal architecture of a hard disk and its associated terminology.

Hard disk geometry and terminology