[RFC] ATA host-protected area (HPA) device mapper?
From: Jeff Garzik
Date: Thu Jun 08 2006 - 23:42:49 EST
As I just mentioned on linux-ide in another email:
libata should -- like drivers/ide -- call the ATA "set max" command to
fully address the hard drive, including the special "host-protected
area" (HPA). We should do this because the Linux standard is to export
the raw hardware directly, making 100% of the hardware capability
available to the user (and, in this case, Linux-based BIOS and recovery
However, there are rare bug reports and general paranoia related to
presenting 100% of the ATA hard drive "native" space, rather than the
possibly-smaller space that the BIOS chose to present to the user.
My thinking is that [someone] should create an optional, ATA-specific
device mapper module. This module would layer on top of an ATA block
device, and present two block devices: the BIOS-presented space, and
Such a module would make it trivial for users to ensure that partition
tables and RAID metadata formats know what the BIOS (rather than
underlying hard drive) considers to be end-of-disk.
Comments? Questions? Am I completely insane? ;-)
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