4.1.13. /etc/sysconfig/harddisks
The /etc/sysconfig/harddisks file tunes the hard drive(s). An administrator can also use /etc/sysconfig/hardiskhd[a-h] to configure parameters for specific drives.
Do not make changes to this file without careful consideration. By changing the default values, it is possible to corrupt all of the data on the hard drive(s).
The /etc/sysconfig/harddisks file may contain the following:
USE_DMA=1, where setting this value to 1 enables DMA. However, with some chipsets and hard drive combinations, DMA can cause data corruption. Check the hard drive documentation or with the manufacturer before enabling this option. By default, this entry is commented out, and therefore disabled.
Multiple_IO=16, where a setting of 16 allows for multiple sectors per I/O interrupt. When enabled, this feature reduces operating system overhead by 30-50%. Use with caution. By default, this entry is commented out, and therefore disabled.
EIDE_32BIT=3 enables (E)IDE 32-bit I/O support to an interface card. By default, this entry is commented out, and therefore disabled.
LOOKAHEAD=1 enables drive read-lookahead. By default, this entry is commented out, and therefore disabled.
EXTRA_PARAMS= specifies where extra parameters can be added. By default, there are no parameters listed.