zpool upgrade -V [PSARC/2007/482 FastTrack timeout 08/30/2007]

[Matthew Ahrens]

James Carlson wrote:
> Lin Ling writes:
>> This is to make it consistent with the existing zfs version setting:
>>
>>           zfs set version=n <dataset>
>>           zfs upgrade -V n <dataset>
>>
>> 'zpool upgrade' does more than just setting the version,
> 
> Sure; understood.
> 
>> it provides mechanism for listing pool versions as well.
>> Having 2 ways to set the version seems reasonable to me.
> 
> That's the question I'm asking.  Why is that reasonable?  It seems
> odd.

Since we're exposing the both zfs and zpool "version" as a property, it 
makes sense to be able to change it with "zfs set".  Since we've established 
the precedent of "zpool upgrade" (and it has additional capabilities, eg. 
"zpool upgrade -a" and "zfs upgrade -r"), it makes sense to have that as well.

Granted, if we could redo the interface from scratch, it would probably be 
better to only change the version with "zfs/zpool set version"[*], and only 
get version information with "zfs/zpool upgrade" (or some more appropriately 
named subcommand).  However, given that we can't change the existing "zpool 
upgrade" interface, this seems like the most self-consistent choice.

--matt

[*] The "set" subcommands would require some enhancements, eg since we don't 
have "zfs set -r" but we want "zfs upgrade -r" functionality.  So this isn't 
quite as straightforward as it might first appear.