At Wed, 9 Nov 2011 09:27:53 -0000, Matthew Law wrote: > > On Wed, November 9, 2011 3:10 am, MORITA Kazutaka wrote: > > Different VMs can use different gateways, so if there are many VMs, > > the gateway cannot be a bottleneck. Our goal is not to provide the > > combined bandwidth of many disks to one VM, but rather to achieve > > scalability; Sheepdog provides enough bandwidth to each VM even if > > many VMs use Sheepdog at the same time. > > How is the gateway node decided? Perhaps we could add this to the > documentation to explain to anyone who jumped to the same (wrong!) > conclusion as me? :-) You can specify it with qemu command line arguemnts. It is localhost:7000 by default. See also: https://github.com/collie/qemu/blob/master/qemu-options.hx#L1796 > > I think for my use case and for the majority of people 'enough bandwidth' > is simply that the VMs do not 'feel' slow when reading and writing and > that I/O is predictable. Nobody can expect clustered storage of this type > to perform like a high performance disk array (this is not the use case). > If it scales well, performs predictably and I/O latency is acceptable then > I think it will appeal to many. > > Perhaps the sheepdog home page could add a section something like this: > > You should consider Sheepdog if you are looking for clustered storage that: > > * Is 'scale-out', with no single point of failure > * Is simple to setup and use (secured at the network layer) > * Is compatible with KVM via QEmu (Xen support is coming later...) > * Works at the block-level > * ... > > You should not consider Sheepdog if you are looking for: > > * High bandwidth/low latency storage ('scale-up') > * Fine grained authentication and authorization of storage nodes > * Works at the file level (clustered file system) > * Tiering > * ... > > Just a suggestion. Thanks! I've added those description to Sheepdog top page: http://www.osrg.net/sheepdog/ Thanks, Kazutaka > > Thanks, > > Matt. > > > -- > sheepdog mailing list > sheepdog at lists.wpkg.org > http://lists.wpkg.org/mailman/listinfo/sheepdog |