Add sparse file support to cpio [PSARC/2008/727 Self Review]

[Darren J Moffat]

Garrett D'Amore wrote:
> I have since learned, from the project team, that this problem is 
> primarily centered around solving issues with Live Upgrade.  They are in 
> a bind on timing, because they are coming up on a key deliverable date.  
> Redesign of the file format, and resetting the testing that has already 
> been done, would be detrimental to some key deliverables around Live 
> Upgrade and Solaris 10.
> 
> Therefore, I recommend an alternate proposal, which I think might 
> satisfy most of the participants here.
> 
> 1) Relegate the ascii_sparse and odc_sparse arguments, and the 
> associated file formats to "undocumented" status.  That is, they won't 
> be documented in the man pages.  This way nobody should have to worry 
> too much about dealing with these file formats portably.  (Neither AT&T, 
> nor GNU, nor star, ever needs deal with them.)  These arguments and file 
> formats will have "Project Private" binding.
> 
> 2) File a contract for their use by the LU (or any other projects) that 
> need them.  (At the same time, we should be giving advice to these 
> projects that they should try to convert to use pax if possible.)
> 
> 3) Anyone else looking for sparse file support should be strongly urged 
> to use the existing pax (or star, if you prefer.   I don't want to get 
> into a debate about Sun pax vs. star vs GNU tar.  Its not this case.)
> 
> This would allow the project to go forward with their existing code, 
> with minimal disruption to their plans, and minimal disruption to 
> "documented" formats that external parties (star, GNU tar, AT&T) have to 
> be prepared to accept.

I agree with this proposed direction.  Particularly sinve Live Upgrade 
is not in OpenSolaris which uses the newly designed that shares no code 
Snap upgrade instead.

-- 
Darren J Moffat