[Engine-devel] VM Payload feature

[Shahar Havivi]

On 23.01.12 09:39, Joseph VLcek wrote:
> 
> On Jan 22, 2012, at 3:09 AM, Oved Ourfalli wrote:
> 
> > 
> > 
> > ----- Original Message -----
> >> From: "Ayal Baron" <abaron at redhat.com>
> >> To: "Oved Ourfalli" <ovedo at redhat.com>
> >> Cc: engine-devel at ovirt.org
> >> Sent: Thursday, January 19, 2012 4:05:08 PM
> >> Subject: Re: [Engine-devel] VM Payload feature
> >> 
> >> 
> >> 
> >> ----- Original Message -----
> >>> Hey all,
> >>> 
> >>> Continuing the discussion about Aeolus instance data injection to a
> >>> VM
> >>> (http://lists.ovirt.org/pipermail/engine-devel/2012-January/000423.html)
> >>> we propose a new VM Payload feature.
> >>> 
> >>> The following wiki page contains a description page of the feature.
> >>> http://www.ovirt.org/wiki/Features/VMPayload
> >>> 
> >>> Please read and review.
> >>> There are several approaches there, and we wish to head your
> >>> opinions
> >>> and thoughts about them.
> >>> 
> >>> Once we agree on an approach, we will start designing.
> >> 
> >> Permanent payload availability requires determining where the payload
> >> is stored.
> >> Makes sense to me to store it together with the VM disks on the
> >> storage domain, but that requires the small object store which will
> >> not be available in the coming version (payloads can be large and
> >> keeping them in the DB and passing over the net every time the VM is
> >> run doesn't make much sense).
> >> 
> > I guess we can start with storing it in the database, with some size limitation, and move it to the storage domain later on.
> > 
> >> Wrt availability, I don't see a reason to exclude attaching both a CD
> >> and a payload via another CD at the same time (i.e. multiple
> >> devices).
> >> 
> >>> 
> >>> Thank you,
> >>> Oved
> >>> _______________________________________________
> >>> Engine-devel mailing list
> >>> Engine-devel at ovirt.org
> >>> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >>> 
> >> _______________________________________________
> >> Engine-devel mailing list
> >> Engine-devel at ovirt.org
> >> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >> 
> 
> 
> 
> My perspective is that of the end user, the instance retrieving the data.
> 
> From a functional standpoint I would like to see similar performance to
> what EC2 provides. AWS EC2 user data is limited to 16K. This limit
> applies to the data in raw form, not base64 encoded form.
> see: 
> http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/instancedata-data-categories.html
> 
> I am concerned about the 512k limit as mentioned in the notes
> of: http://www.ovirt.org/wiki/Features/VMPayload
> "if the content of the file is bigger the 512K it will pass an nfs
> share for vdsm to fetch the file/s"
> 
> Please confirm:
> - Will it be possible to pass user data to larger than 512k?
> - If so what will the instance need to do in order to retrieve
>    user-data bigger than 512k.
> - What will the MAX size supported for the user-data?
512k is a suggestion,
we don't want to embed large files in the verb that ovirt calls vdsm, instead
if it bigger then 512k/1M we will pass urls/nfs path of the files and VDSM
will add them to the iso file.
there is not limitation of size...
> 
> Thank you.
>     Joe VLcek
>