[pve-devel] RFC: qemu-server : add cloudinit support

Alexandre DERUMIER aderumier at odiso.com
Fri Jun 19 08:11:53 CEST 2015


>>Yes, because of the second condition: 
>>«2. Must be a un-partitioned block device (/dev/vdb, not /dev/vdb1)» 
>>
>>Qemu's vvfat includes an MBR with the filesystem being the first partition. 
>>In my tests the second condition doesn't apply if it has a label, at least on 
>>linux. 

Ok.
with cdrom it seem to work without label (tested with debian)

the code is here:
https://github.com/number5/cloud-init/blob/74e61ab27addbfcceac4eba254f739ef9964b0ed/cloudinit/sources/DataSourceConfigDrive.py
I don't have read it yet.

can you send qemu patch and qemu-server patches ? I would like to test it with windows.


----- Mail original -----
De: "Wolfgang Bumiller" <w.bumiller at proxmox.com>
À: "aderumier" <aderumier at odiso.com>
Cc: "pve-devel" <pve-devel at pve.proxmox.com>, "dietmar" <dietmar at proxmox.com>
Envoyé: Vendredi 19 Juin 2015 08:02:07
Objet: Re: [pve-devel] RFC: qemu-server : add cloudinit support

> "The following criteria are required to as a config drive: 
> Must be formatted with vfat or iso9660 filesystem or have a filesystem label 
> of config-2 
> " 
> 
> so, does it need to be really labelled config-2 ? 

Yes, because of the second condition: 
«2. Must be a un-partitioned block device (/dev/vdb, not /dev/vdb1)» 

Qemu's vvfat includes an MBR with the filesystem being the first partition. 
In my tests the second condition doesn't apply if it has a label, at least on 
linux. 

-- 
> On June 19, 2015 at 7:55 AM Alexandre DERUMIER <aderumier at odiso.com> wrote: 
> 
> 
> also cloud-init windows seem to support vfat configdrive 
> 
> "Add support for VFAT ConfigDrive" 
> https://github.com/stackforge/cloudbase-init/commit/2026ee8e0f766f91cf62904ceca3de7382eea787 
> 
> 
> and cloud-init documentation say: 
> http://cloudinit.readthedocs.org/en/latest/topics/datasources.html 
> 
> "The following criteria are required to as a config drive: 
> Must be formatted with vfat or iso9660 filesystem or have a filesystem label 
> of config-2 
> " 
> 
> so, does it need to be really labelled config-2 ? 
> 
> 
> ----- Mail original ----- 
> 
> De: "Wolfgang Bumiller" <w.bumiller at proxmox.com> 
> À: "aderumier" <aderumier at odiso.com> 
> Cc: "dietmar" <dietmar at proxmox.com>, "pve-devel" <pve-devel at pve.proxmox.com> 
> Envoyé: Jeudi 18 Juin 2015 15:16:34 
> Objet: Re: [pve-devel] RFC: qemu-server : add cloudinit support 
> 
> Hey Alexandre, 
> I don't know if you're already tinkering with rsyncing the iso images, 
> and wanted to let you know that I'm currently experimenting with qemu's 
> vvfat drive option. According to the source it should work across 
> migrations as long as it's used read-only. I tested migrating in a 
> virtual testcluster and it seemed to work. 
> It basically takes a directory, loads the list of contained files and 
> presents the guest OS with a fat16 formatted partition on a block device. 
> The downside of it is that we need the qemu patch I posted earlier to 
> label the partition, as cloud-init needs it to be labeled "config-2", 
> but qemu's vvfat default is hardcoded to "QEMU VVFAT". 
> The change is small enough though, so maybe they even accept it 
> upstream... 
> 
> On Wed, Jun 17, 2015 at 12:58:53PM +0200, Alexandre DERUMIER wrote: 
> > >>I would generate a Digest using all cloud-init related values, and 
> > >>re-gererate 
> > >>the iso at VM start 
> > >>if the digest has changed. 
> > 
> > Ok. Maybe can be generate the cloudinit iso file with vmid-digest.iso ? 
> > Like this no need to store the dgest in vmid.conf ? 
> > 
> > Also, Do we need to set theses changed values in pending or not ? 
> > 
> > 
> > ----- Mail original ----- 
> > De: "dietmar" <dietmar at proxmox.com> 
> > À: "Wolfgang Bumiller" <w.bumiller at proxmox.com>, "aderumier" 
> > <aderumier at odiso.com> 
> > Cc: "pve-devel" <pve-devel at pve.proxmox.com> 
> > Envoyé: Mercredi 17 Juin 2015 11:40:24 
> > Objet: Re: [pve-devel] RFC: qemu-server : add cloudinit support 
> > 
> > > I would like to known when do you want to generate the cloudinit iso. 
> > > 
> > > If user change settings (ips,hostname,...), do we want to apply them 
> > > directly 
> > > to configuration ? 
> > > or do we want to put them as pending ? (for ip can be ok, for hostname 
> > > that 
> > > seem strange if user want to rename his vm). 
> > > 
> > > Advantage to pending, is that we can simply regenerate the iso at vmstart 
> > > if 
> > > pending changes exist. 
> > > and user can also revert with if wrong settings. 
> > 
> > I would generate a Digest using all cloud-init related values, and 
> > re-gererate 
> > the iso at VM start 
> > if the digest has changed. 
> > 
> > 
> 


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