NOTE: viewing this document needs a terminal larger than 80 chars (175 chars).
>1TB is not supported in 32 bit kernel.
Current behavior of main disk target drivers (sd/ssd/cmdk) in Nevada.

			>2TB							1-2TB							< 1TB
	------------------------------------------------------	-------------------------------------------------------	       	-------------------------------------------
	blank		GPT	vtoc/		x86 legacy	vtoc		default  	 no VTOC/	GPT		GPT		vtoc/default	no vtoc/
	nolabel			+x86 w/legacy 	mbr with no 			vtoc	  	no default 							no default
				mbr +sol part	solaris part	
				default vtoc
DKIOCGVTOC
current	ENOTSUP		ENOTSUP	SPARC success	ENOTSUP		SPARC success	n/a(I*XXX)	ENOTSUP		ENOTSUP		ENOTSUP		success	  	EINVAL (*I)
				x86 ENOTSUP			x86 ENOTSUP
change: EOVERFLOW	"	EOVERFLOW	EOVERFLOW	EOVERFLOW	EOVERFLOW	EOVERFLOW	"		"		"		"
DKIOCGGEOM
cur:	ENOTSUP		ENOTSUP	SPARC success	ENOTSUP		SPARC success	n/a(I*)		ENOTSUP		ENOTSUP		ENOTSUP		success		EINVAL (*I)
				x86 ENTOSUP			x86 ENOTSUP
change:	"		"	success		EINVAL		success		success		EINVAL		"		"		"		"
DKIOCGAPART
cur: 	ENOTSUP		ENOTSUP SPARC success	ENOTSUP		SPARC success	n/a		ENOTSUP		ENOTSUP		ENOTSUP		success      	EINVAL
				x86 ENOTSUP			x86 ENOTSUP
change: "		"	ENOTSUP		"		ENOTSUP		ENOTSUP		"		"		"		"		"
DKIOCSVTOC
cur:	ENOTSUP		ENOTSUP	ENOTSUP		ENOTSUP		ENOTSUP		n/a		ENOTSUP		ENOTSUP		success		success		success/(*III)
change: EOVERFLOW	EOVRFLW	EOVRFLOW	EOVRFLOW	EOVERFLOW	EOVERFLOW	EOVERFLOW	EOVEFLOW	"		"		"
DKIOCSAPART
cur:	ENOTSUP		ENOTSUP ENOTSUP 	ENOTSUP		ENOTSUP		n/a		ENOTSUP		ENOTSUP		ENOTSUP		success		EIO
change:	"		"	"		"		"		ENOTSUP		"		"		"		"		"
DKIOCSGEOM
cur:	x86 EIO		success	success		x86 EIO		x86 EIO		n/a		x86: EIO 	success	       success		success		x86 EIO	
	SPARC success				SPARC n/a	SPARC success			SPARC success							SPARC success
change: success		"	"		" 		success		success		"		"		"		"		"
DKIOCPARTINFO:
cur:	p0-4raw success success	p0-4raw success	p0-4rawsuccess	p0-4rawsuccess	n/a		p0-4raw success	success		success		success	 	p0-4raw success
	else EIO		else EIO	else EIO	else EIO			else EIO	bug						else EIO
change:EOVERFLOW	EVERFLW EOVERFLOW	EOVERFLOW	EOVERFLOW	EOVERFLOW	EOVERFLOW	EOVERFLOW	success		"		"
DKIOCG_PHYGEOM
cur:	ENOTSUP 	ENOTSUP ENOTSUP		ENOTSUP		ENOTSUP		n/a		ENOTSUP		success		success		success		success
change: success		success	success		success		success		success		success		"		"		"		"
DKIOCG_VIRTGEOM (*IV)
cur: 	ENOTSUP		EINVAL	ENOTSUP		ENOTSUP		ENOTSUP		n/a		ENOTSUP		>8G EINVAL	>8G EINVAL	>8G EINVAL 	>8G EINVAL
														
change:	EINVAL		"	EINVAL		EINVAL		EINVAL		EINVAL		EINVAL 		"		"		"		"
DKIOCGEXTVTOC:
new:	ENOTSUP		ENOTSUP	success		EINVAL		success		success		EINVAL		ENOTSUP		ENOTSUP		success		EINVAL
DKIOCSEXTVTOC (*III)
new:	success		success	success		EINVAL		success		success		success(*III)	success		success		success		success (*III)
DKIOCEXTPARTINFO:
new:	p0-4rawsuccess	success	success		p0-4rawsuccess	success		success		p0-4rawsuccess	success		success		success		p-4rawsuccess
	else EIO				else EIO					else EIO							else EIO
	


I: SPARC IDE fixed disk drives. if the disk does not have any vtoc label, we don't 
actually assume a default vtoc to allow access to disk nodes, but DKIOCGGEOM and
GVTOC succeed). This functionality will not be carried over to disks > 1TB.
IDE support on SPARC is currently limited to 128GB disks.

II.  Currently sd driver recognizes a disk > 1TB with vtoc8 on it on SPARC.
DKIOCSVTOC, DKIOCSAPART, will still fail on such a disk with ENOTSUP. DKIOCGAPART and
GVTOC  GGEOM will succeed.

III. DKIOCSVTOC requires a setting of geometry by SGEOM if no vtoc/no default
is assumed on SPARC else fails with EIO.
If there is a legacy MBR on x86 with no solaris partition DKIOCSVTOC and
DKIOCEXTVTOC will fail.

IV: DKIOCG_VIRTGEOM is supposed to fail on > 8GB disks. Current code does
not always enforce that.

V.This document explains the behavior for 512 byte target block sizes.