[illumos-Developer] WEBREV 719 beadm should support non-IPS BEs

[Alexander Stetsenko]

On 02/28/2011 12:56 AM, Bill Sommerfeld wrote:
> On 02/27/11 12:57, Alexander Stetsenko wrote:
>>> first, this seems really messy, and I don't see what this has to do
>>> with IPS -- both IPS and live upgrade put filesystems containing BE's
>>> under $rpool/ROOT.
>> no, every pool containing ROOT filesystem (<poolname>/ROOT) are
>> considered to be BE root container.
> Sure, but it's not common to see them in pools other than the root 
> (unless you're moving the root filesystem from one pool to another).
>
>> it seems strange for me.
>> You can create pool1/ROOT/aaa pool2/ROOT/bbb etc. and beadm will
>> show aaa and bbb in be list.
>
> Just because beadm lists a boot environment doesn't mean it's complete 
> and bootable.
of course, and libbe does not validate BE content.
>
>
> Is your concern around filesystems that don't contain a complete boot 
> environment?  How does your proposal address this?  It looks to me 
> like you're just changing what filesystem names are interpreted as 
> boot environments; you're not changing any validation of filesystems 
> as bootable.
Yes, this is just filesystem names interpretation.
>
>>> second, it seems like you could get by with a single parameter:
>>>
>>> BENAME_PREFIX, defaulting to ROOT/
>>>
>>> why have two tunables where one is sufficient?
>> one parameter should make 2 things:
>> fist is to point out there is no special ROOT container for be, and new
>> be is created in rpool root.
>
> why is this distinction necessary?  you need to go beyond proof by 
> vigorous repeated assertion.
>
> the presence of a '/' in the prefix would be sufficient to show that 
> all BE's must be inside a particular filesystem path.
Using BENAME_PREFIX instead of previos two parameters will result in a 
possibility to have the real rpool
that conflicts with BENAME_PREFIX value, for example we have rpool/ROOT 
but BENAME_PREFIX="syspool/ROOT/".
How should libbe behave in that case? libbe is looking for active BE 
filesystem by '/' mountpoint,
but active be filesystem name will not starts from $BENAME_PREFIX - 
libbe panic !!!

>
>
> I'll also note in passing that $rpool/ROOT is very useful as a place 
> to set inherited filesystem properties which affect all boot 
> environment filesystems but no other filesystems.  For instance, I 
> typically set copies=2 and compression=on on $rpool/ROOT.
I`m agree, It is much better to have distinct BE container than to mess 
BEs with other datasets in rpool fs.
>
>                     - Bill
>
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