On Wed, May 1, 2013 at 7:37 PM, Lance Albertson <[email protected]> wrote: > [moving this to ganeti-devel since its more of an architecture question] > > On Wed, May 1, 2013 at 10:24 AM, <[email protected]> > wrote: >> >> Hi Lance, >> >> I don't see in the proposal the external storage interface mentioned, and >> indeed I am not sure we should use that to provide gluster support. Why not >> going for a "gluster" type inside Ganeti? This would also be the only way to >> make sure the qemu gluster inteface can be used easily. >> >> Thanks, >> >> Guido > > I haven't used the external storage provider much myself but from reading > the design doc it seems to fit within the typical use case for that > provider. Why do you feel it doesn't fit well with it and that it requires > its own type? Perhaps I need to take a closer look at how the qemu gluster > interface actually works. Should we focus on getting the qemu gluster > interface working for Ganeti, the more typical way you use gluster with it > mounted on the Ganeti node, or try and focus on both? I think the qemu > gluster interface is the most ideal personally.
My feeling is that the external storage is for allowing admins to add support for their own site-specific SANs/devices, but not for something that we want to provide full support from Ganeti. I think we should focus on qemu+gluster and just fallback to the other method (if feasible without huge extra work). We should also focus on providing gluster through Ganeti nodes (aka. self-configuring of gluster via ganeti node add). The reason I felt that to use the qemu-gluster you need gluster as a primary type is that ext types are opaqua to Ganeti. As such they can only export "one block device" which qemu then uses. If we want to provide a hypervisor-specific way (like we do for gluster and ceph) we need for the hypervisor to be able to behave differently depending on the storage type, which we can't do with ext, since the backend is opaque then. :) Thanks, Guido > > Thanks- > > -- > Lance Albertson > Director > Oregon State University | Open Source Lab -- Guido Trotter Ganeti Engineering Google Germany GmbH Dienerstr. 12, 80331, München Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Geschäftsführer: Graham Law, Katherine Stephens Steuernummer: 48/725/00206 Umsatzsteueridentifikationsnummer: DE813741370
