Open Stack

Thanks a lot

Aren't there problems to change the type of an image (qcow2 --> raw) if
there are VMs instantiated using that image ?

Thanks again, Massimo

2017-03-29 3:59 GMT+02:00 Fei Long Wang <feilong at catalyst.net.nz>:

> Hi Massimo,
>
> Thanks for providing more information. As you can see from David's blog
> and the script (https://github.com/dmsimard/migrate-glance-backend). The
> most tricky part is how to keep current image id, otherwise, all the
> existing instances will fail to rebuild. The way I'm suggesting can help
> keep the image id and don't have to create another image. The steps are as
> follow:
>
> 1. Download and re-upload
>
>     1.1 Iterate tenants and images, download images, convert images from
> qcow to raw
>
>     1.2 upload images to RBD by following the same way like this
> https://github.com/openstack/glance_store/blob/master/
> glance_store/_drivers/rbd.py#L426
>
> 2. Create new location for each image based on the location get from #1.2.
> For this step, it would be nice to enable  *show_multiple_locations=True*
> Note: Glance team would suggest to disable this after your migration. However,
> if you want to use CoW, you may still need to keep it :(
>
> 3. Delete old locations based on GlusterFS
>
> 4. All done
>
>
> *NOTE*:
>
> 1. For step #2 and #3, you could follow this blog about how
> https://www.sebastien-han.fr/blog/2015/05/13/openstack-
> glance-use-multiple-location-for-an-image/
>
> 2. Step 1 and 2 can be done before your downtime window.
>
> 3. Technically, you can keep the two locations without deleting the old
> location or at least getting a more smoother during migration by using
> location strategy. For this case, you can set:
>
> *     stores=rbd,file*
>
>      *location_strategy=store_type*
>
>      *store_type_preference=rbd,file*
>
>      That means if there are 2 locations, Glance will try to use the RBD
> location first, then filesystem location. See more info
> https://github.com/openstack/glance/blob/master/etc/glance-api.conf#L4388
>
>
>
> On 29/03/17 02:02, Massimo Sgaravatto wrote:
>
> First  of all thanks for your help
>
> This is a private cloud which is right now using gluster as backend.
> Most of the images are private (i.e. usable only within the project),
> uploaded by the end-users.
> Most of these images were saved in qcow2 format ...
>
>
> The ceph cluster is still being benchmarked. I am testing the integration
> between ceph and openstack (and studying the migration) on a small
> openstack testbed.
>
>  Having the glance service running during the migration is not strictly
> needed, i.e. we can plan a scheduled downtime of the service
>
> Thanks again, Massimo
>
>
> 2017-03-28 5:24 GMT+02:00 Fei Long Wang <feilong at catalyst.net.nz>:
>
>> Hi Massimo,
>>
>> Though I don't have experience on the migration, but as the glance RBD
>> driver maintainer and image service maintainer of our public cloud
>> (Catalyst Cloud based in NZ), I'm happy to provide some information. Before
>> I talk more, would you mind sharing some information of your environment?
>>
>> 1. Are you using CoW of Ceph?
>>
>> 2. Are you using multi locations?
>>
>> show_multiple_locations=True
>>
>> 3. Are you expecting to migrate all the images in a maintenance time
>> window or you want to keep the glance service running for end user during
>> the migration?
>>
>> 4. Is it a public cloud?
>>
>>
>> On 25/03/17 04:55, Massimo Sgaravatto wrote:
>>
>> Hi
>>
>> In our Mitaka cloud we are currently using Gluster as storage backend for
>> Glance and Cinder.
>> We are now starting the migration to ceph: the idea is then to dismiss
>> gluster when we have done.
>>
>> I have a question concerning Glance.
>>
>> I have understood (or at least I hope so) how to add ceph as store
>> backend for Glance so that new images will use ceph while the previously
>> created ones on the file backend will be still usable.
>>
>> My question is how I can migrate the images from the file backend to ceph
>> when I decide to dismiss the gluster based storage.
>>
>> The only documentation I found is this one:
>>
>> https://dmsimard.com/2015/07/18/migrating-glance-images-to-a
>> -different-backend/
>>
>>
>> Could you please confirm that there aren't other better (simpler)
>> approaches for such image migration ?
>>
>> Thanks, Massimo
>>
>>
>> _______________________________________________
>> OpenStack-operators mailing listOpenStack-operators at lists.openstack.orghttp://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>
>> --
>> Cheers & Best regards,
>> Feilong Wang (王飞龙)
>> --------------------------------------------------------------------------
>> Senior Cloud Software Engineer
>> Tel: +64-48032246 <+64%204-803%202246>
>> Email: flwang at catalyst.net.nz
>> Catalyst IT Limited
>> Level 6, Catalyst House, 150 Willis Street, Wellington
>> --------------------------------------------------------------------------
>>
>> _______________________________________________ OpenStack-operators
>> mailing list OpenStack-operators at lists.openstack.org
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>
> --
> Cheers & Best regards,
> Feilong Wang (王飞龙)
> --------------------------------------------------------------------------
> Senior Cloud Software Engineer
> Tel: +64-48032246 <+64%204-803%202246>
> Email: flwang at catalyst.net.nz
> Catalyst IT Limited
> Level 6, Catalyst House, 150 Willis Street, Wellington
> --------------------------------------------------------------------------
>
>
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