IAM
======
Open Inception: Multiple disk sector size support (2008/769)
		Submitter: Larry Liu
		Owner: Mark Carlson
		Exposure: open

SUMMARY
=======
This project is to enable Solaris to support disks with larger 
	sector size than the traditional 512 bytes. For example, sectors
	may be 1 KByte, 2KB or 4KB.


ISSUES
======

 PSARC 2008/769:Multiple disk sector size support.
 Submitter:	Larry Liu
 Owner:		Mark Carlson
 
#ident "@(#)issues	1.3 09/01/14 SAC"

PSARC 2008/769:	Multiple disk sector size support.
Submitter:	Larry Liu
Owner:		Mark Carlson

Issues for inception (01/14/2009):

jdc-1	Is phase II under review here as well?  (Assuming it's later,
	and things like volume-config and ufsdump/ufsrestore aren't
	part of this review.)

team	No. phase II will be reviewed later, through a full case or fast track.
	BTW, we are seeking advice on whether modules like UFS and LVM, which are in
	sustaining mode, need to be supported.

jdc-2	What's the reason for omitting dad(7D) and the effect on the
	product?  Do some SPARC platforms then lag x86?

team	dad(7D) is for IDE disk driver on SPARC. Since IDE(PATA) standard is no
	longer being developed, we assume there will be no larger sector IDE
	disks. However, if there is a request from IDE HDD vendors, dad(7D) can be
	changed similar to what was done for sd(7D).

jdc-3	Should any virtual disk drivers be changed to support large
	sectors?

team	Yes. Both target drivers on Xen and LDOM will be changed to support
	large sector. We already worked out a prototype on Xen to work on large
	sector disk. LDOM is under investigation.

jdc-4	directio(3C) references "sectors" -- are these now large ones
	or default 512 byte?

team	These are large ones. The I/O must be aligned with the device sector
	size (the native sector size of the disk).

jdc-5	Do SCSI_CAP_{SECTOR_SIZE,TOTAL_SECTORS} reflect the larger
	size?

team	Yes. They reflect to the larger sector size and real disk capacity.

jdc-6	Are any backup tools affected by this change?  How are we
	engaging third-party application developers?

team	The back up tools are under investigation. If they are sector size
	sensitive, they will need to be changed to adopt the large sector size. The
	engineering team is contacting Veritas and the ISV team about the change to
	their software. We will document that the third-party application
	developers need to change their software if they are sector size sensitive.

jdc-99	nit: work with your case owner/intern on interface table;
	imports aren't right.

team	will do


chris horne: what are we doing with the buf structure?
 
THE NEXT STEP
=============
ADVICE: jdc-1 and glenn skinner - recommend team to get the prototype done as soon as 
possible to understand what the issues are and the tradeoffs are.

Team to talk to Chris Horne to get better understanding of his issue
prior to commitment.