On 01/21/10 02:56 PM, Sanjay Nadkarni wrote:
> On 01/21/10 09:59 AM, Dave Miner wrote:
>> On 01/21/10 12:12 AM, sanjay nadkarni wrote:
>>> Dave Miner wrote:
>>>> On 01/12/10 04:16 AM, sanjay nadkarni (Laptop) wrote:
>>>>> Caimanics,
>>>>>        Please review the requirements documents for replication in
>>>>> OpenSolaris.  This  provides the the  Flash type functionality but
>>>>> includes support for zones.
>>>>>
>>>>
>>>> Intro:
>>>>
>>>> I don't think there's anything preventing zones from being included in
>>>> a master image created by DC and deployed by the GUI or text
>>>> installer. Getting the zones configured correctly after deployment of
>>>> the image is likely an entirely manual process, but otherwise I don't
>>>> know of a reason this couldn't work.  To me, the main reason
>>>> replication is desired is that it can be hard to script up all the
>>>> things you'd like to configure into DC scripts; replication allows for
>>>> a manual build-out of the master and then fast, reliable duplication.
>>>>
>>> Agreed.  I will fix that.
>>>
>>>> Interesting distinction of replication vs. recovery.  I'd never put it
>>>> quite that way, but I think it's probably the right expression.
>>>>
>>>> Goals:
>>>>
>>>> You didn't mention zones p2v here; probably should be explicit one way
>>>> or the other.
>>>>
>>> Sarah mentioned that too. I need to think about this a bit more to
>>> understand the ramifications.
>>>> Requirements:
>>>>
>>>> 5.  I don't see how compression is related to portability, nor why
>>>> multiple compression options relate (or are even required, though I
>>>> agree that multiple should be possible, which is what I think you
>>>> really meant to say here).
>>>>
>>> I was really thinking about portability in terms of size i.e. easy to
>>> move it around.  An uncompressed image can be 10's of GB.  While it can
>>> be moved, its not easy.
>>
>> Mobility is perhaps the term you really want to use.  But on 1G or 10G
>> networks, moving 10 GB isn't actually that time-consuming, so while I
>> don't have a problem with defaulting to compressing these things
>> somehow, allowing for non-compressed seems trivial.
>>
>>
>>>> 7.  I'm not following how the packages would get used, or why it's
>>>> this tool's problem; it seems like a requirement on the installers
>>>> that are deploying such an image to appropriately deal with attributes
>>>> of the system.  Otherwise you're seemingly creating the requirement
>>>> that the creation tool must be omniscient about all possible
>>>> architectures that the image might be applied to in the future.
>>>>
>>> I was unclear.  By the term "tool" I mean the installers need to provide
>>> the ability to add pkgs.I do expect the installers to provide the
>>> capability to add pkgs.  The only reason to include the IPS repo
>>> information in the image is a hint as to where to pick up the pkgs.  Of
>>> course I expect this can be overridden.   I also realized that I missed
>>> capturing this requirement as a requirement on other projects.
>>>> Metadata:
>>>>
>>>> Why is IPS publisher info necessary in the metadata?  How would we use
>>>> it before the image is actually laid down, at which time we can just
>>>> grab it from the image itself?
>>> The IPS publisher information was included as a hint to the installer to
>>> pull in the required pkgs.  For reasons I cannot fathom now, I was
>>> conflating the need for this at install time.  That of course is not
>>> required since the system will already be running.
>>>> Similarly for zones and other system configuration.  Broadly, is our
>>>> goal to replicate both the contents and the configuration, or just the
>>>> contents?
>>> Here's I was mainly thinking about providing better information  about
>>> contents of the image.  For example, users could create one master image
>>> which based on a system with 2 zones which are configured for Oracle
>>> with 2 VNICS.  Another image could have 5 zones of with 2 are configured
>>> for Apache webservers and others have MySQL.  As a user I would like to
>>> know the contents of those archives.
>>
>> OK, I understand better what you're trying to solve.
>>
>>>
>>>> Goal 1 seemed to imply the latter to me, but the use cases seem to be
>>>> leading toward the former. Need clarity here, I think.
>>>>
>>>> The pool information seems orthogonal to replicating a BE.  It seems
>>>> possibly more applicable to a recovery scenario, though I can't say
>>>> I've entirely convinced myself of that, either.
>>> I was approaching this with the idea that the image should not only
>>> replicate the BE, but should also  provide a hint of the type of
>>> stability required. for example mirrored root. The ability to override
>>> this must exist.  But again, if a user queries the image, it would be
>>> useful to have this type of information when choosing the target system.
>>
>> I don't quite buy into the image *requiring* a particular storage
>> configuration.  Information on what the original configuration was
>> seems like it could be helpful, I suppose.
>>
>>>>
>>>> Requirements on other projects:
>>>>
>>>> I'm not sure installadm is the tool to provision the master images.
>>> I would like to think about this a bit more.
>>>> One approach that occurs to me is to publish the stream as the
>>>> contents of the package (might need a new action type for that to do
>>>> it well), with the metadata expressed as tags of that package.
>>> That jives with my thoughts too.
>>>> This seems to meet most, if not all, of the Requirements and might
>>>> limit the necessary changes in the applications a bit.
>>> Can you elaborate ?
>>>
>>
>> If the stream is just a package that gets laid down, there's very
>> little additional work required in the installers - we already know
>> how to install packages.  The only thing that would seem to be
>> necessary to add to the installer then is to de-encapsulate the
>> installed image from the stream package.
> All true,  except that the pool needs to be created before the image can
> be laid down and hence I was planning on the image providing  hints
> about storage layout.
>

That seems fine, especially if the hints were in the form of an AI 
manifest (fragment?) ;-)

Dave


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