[Engine-devel] VM Payload feature

[Andrew Cathrow]

----- Original Message -----
> From: "Shahar Havivi" <shaharh at redhat.com>
> To: "Joseph VLcek" <jvlcek at redhat.com>
> Cc: "Oved Ourfalli" <ovedo at redhat.com>, engine-devel at ovirt.org, "Michal Fojtik" <mfojtik at redhat.com>, "David
> Lutterkort" <dlutter at redhat.com>
> Sent: Monday, January 23, 2012 10:07:30 AM
> Subject: Re: [Engine-devel] VM Payload feature
> 
> 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...

If we're talking about URLs keep in mind SELinux restrictions (eg. passing a URL to a HTTP hosted IS will be blocked, iirc)

> > 
> > Thank you.
> >     Joe VLcek
> > 
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