Open Stack

> -----Original Message-----
> From: Mārtiņš Jakubovičs [mailto:martins at hostnet.lv]
> Sent: 18 December 2013 11:06
> To: openstack at lists.openstack.org
> Subject: [Openstack] XenServer support
> 
> I want to create small cloud but in testing I faced with many
> issues and it looks like OpenStack + XenServer is not usable for production.

Just to point out that OpenStack+XenServer certainly is useable - and being aggressively used - in production.  The production cases that I'm aware of do not use the feature that is broken in this instance, host aggregates, which is also one of the least well tested areas of the integration.  

> - Can't aggregate hosts. (After patch it is going to work, but in
> XenServer second host's PV domU nova-compute won't start anyway
> https://ask.openstack.org/en/question/8392/aggregate-hosts/)

I'm in the process of trying to create a back-port for Havana that will resolve this (https://review.openstack.org/#/c/61712/).  Note that trunk does not suffer from either the original issue or the new one that cropped up.  It's very disappointing that we didn't have the right testing in place to ensure that this functionality wasn't broken for the Havana release, but I'm also working on that.

> - Not normal shared storage support. Isn't possible to resize instances
> with shared storage.

"resize" current expects to be moving the images from one SR to another using rsync.  I agree that this is something that should be addressed - could you raise a bug report on that and give it the "xenserver" tag?

> - Shared storage is important, without shared storage XenServer can't
> create aggregate zone (Resource pool) and use live migration.

Storage in XenServer is based on a UUID.  There is a mode in XenServer 6.2 which can be enabled by setting "relaxed_xsm_check=true" in /etc/xapi.conf which will test whether the SRs are the same based on the UUID and only copy the VDI if it does not exist in the target SR.

If you enable this option, then you can use shared storage on your XenServer hosts with storage live migration, rather than needing to use the pool live migration which does depend on host aggregates.  This may enable you to set up a pool independently of host aggregates and still benefit from the increased speed of pool-based live migration.

Thanks,

Bob