On 01/21/10 01:00 PM, Dave Miner wrote:
> 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?) ;-)
I had not completely thought through the format. However my thought was 
that derived manifests would be a consumer.

-Sanjay

>
> Dave
>
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