zpool autoexpand property [PSARC/2008/353 Self Review]

[George Wilson]

James Carlson wrote:
> Matthew Ahrens writes:
>   
>> The introduction of the 'autoexpand' will allow administrators the
>> ability to enable or disable automatic pool expansion when a Dynamic LUN
>> Expansion event is received.  The syntax for setting the pool property
>> utilizes the "set" subcommand defined in PSARC 2006/577:
>>
>>    # zpool set autoexpand=on <pool>
>>    # zpool create -o autoexpand=on <pool> <device> ..
>>     
> [...]
>   
>>        expanded before the new space is made available to the pool. The
>>        default behavior is "off". This property can also be referred to
>>     
>
> Having been bit by this, I certainly agree with having this feature
> default to "off".  It's surprising when detaching a disk causes the
> rubber band to snap outwards.
>
> However, what explicit command can I use when I want to cause the
> expansion to occur?  With SVM, I would have done my disk manipulations
> (whatever they were) and then finally told SVM to sync up with the
> largest available disk in the pool like this:
>
> 	# metattach d1
>
> Shouldn't there be a command like "zpool grow <pool>"?
>
>   
You can enable the 'autoexpand' property to do this but it does not give 
you the fine-grained control that mentioned above. We did talk about 
having a new 'zpool online' option to expand a given vdev. This should 
be easy to do.

- George