Re: TRIM vs UNMAP vs WRITE SAME and thin devices

[Matthew Wilcox <matthew@wil.cx>]

On Sun, Feb 08, 2009 at 03:06:44PM -0500, Greg Freemyer wrote:
> I found a list of T10 activities just since just Dec. 1, 2008 and it
> is a bit overwhelming.  (ie. 08-356r4 is but one of many recent
> reports)
> 
> http://www.t10.org/new_a.htm
> 
> For those of us that don't live and breath the SCSI spec, is there an
> overview site describing what is going on.

I've been working off 08-149r7.pdf.  I'm sure that's been superseded by
now.  

> 08-356r4 	SBC-3: WRITE SAME unmap bit 	David L. Black 	PDF (56608)	2008/12/10

Probably interesting.  Haven't read it myself.

> 08-356r5 	SBC-3 Thin Provisioning Commands 	Fred Knight, David L.
> Black 	PDF (387549)	2009/01/15

Fred Knight seems to be the main coordinator of this effort, so yes.

> 08-149r7 	SBC - Thin Provisioning 	Frederick Knight 	PDF (281001)	2008/12/08

That's the one I'm working from.

> 08-149r8 	SBC - Thin Provisioning 	Frederick Knight 	PDF (281387)	2009/01/09

A newer version ... thought so.

> 09-011r1 	SBC-3 Thin Provisioning Threshold Notification 	Frederick
> Knight 	PDF (32757)	2009/01/09

Clearly related.

> 08-149r9 	SBC - Thin Provisioning 	Frederick Knight 	PDF (353888)	2009/01/15

Even newer version of what I've been working from.

> 09-012r0 	Minutes: CAP - Thin Provisioning 12/4 con-call 	Frederick
> Knight 	PDF (38063)	2008/12/08

Probably tedious.

> 08-396r3 	SPC-4: Reporting support for all DIF types 	George Penokie
> 	PDF (85358)	2009/01/14

Unrelated, I would think.

I'd go with 08-149r9 to get a good overview.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."