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.

Dave

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