Yes, I meant EBS not ECS. Too many similar acronyms... The thing about the Amazon folk is that they collect a lot of metrics, and pretty much do everything on a fairly empirical basis. This is a huge advantage. Starting thinking about what I could with good metrics and building on the performance characteristics of flash. Turns out ... I can see how this could work (and very, very well). But that requires a much longer write-up than I have time for at the moment.
On Tue, Oct 21, 2014 at 12:11 PM, Dan Genin <daniel.ge...@jhuapl.edu> wrote: > Did you mean EBS? I thought it was generally hard to get the same kind > of performance from block storage that local ephemeral storage provides but > perhaps Amazon has found a way. Life would certainly be much simpler with a > single ephemeral backend. Storage pools ( > https://blueprints.launchpad.net/nova/+spec/use-libvirt-storage-pools) > should provide some of the same benefits. > > > On 10/21/2014 02:54 PM, Preston L. Bannister wrote: > > As a side-note, the new AWS flavors seem to indicate that the Amazon > infrastructure is moving to all ECS volumes (and all flash, possibly), both > ephemeral and not. This makes sense, as fewer code paths and less > interoperability complexity is a good thing. > > That the same balance of concerns should apply in OpenStack, seems > likely. > > > > > On Tue, Oct 21, 2014 at 7:59 AM, Dan Genin <daniel.ge...@jhuapl.edu> > wrote: > >> Hello, >> >> I would like to add to DevStack the ability to stand up Nova with LVM >> ephemeral >> storage. Below is a draft of the blueprint describing the proposed >> feature. >> >> Suggestions on architecture, implementation and the blueprint in general >> are very >> welcome. >> >> Best, >> Dan >> >> ======================== >> Enable LVM ephemeral storage for Nova >> ======================== >> >> Currently DevStack supports only file based ephemeral storage for Nova, >> e.g., >> raw and qcow2. This is an obstacle to Tempest testing of Nova with LVM >> ephemeral >> storage, which in the past has been inadvertantly broken >> (see for example, https://bugs.launchpad.net/nova/+bug/1373962), and to >> Tempest >> testing of new features based on LVM ephemeral storage, such as LVM >> ephemeral >> storage encryption. >> >> To enable Nova to come up with LVM ephemeral storage it must be provided a >> volume group. Based on an initial discussion with Dean Troyer, this is >> best >> achieved by creating a single volume group for all services that >> potentially >> need LVM storage; at the moment these are Nova and Cinder. >> >> Implementation of this feature will: >> >> * move code in lib/cinder/cinder_backends/lvm to lib/lvm with appropriate >> modifications >> >> * rename the Cinder volume group to something generic, e.g., devstack-vg >> >> * modify the Cinder initialization and cleanup code appropriately to use >> the new volume group >> >> * initialize the volume group in stack.sh, shortly before services are >> launched >> >> * cleanup the volume group in unstack.sh after the services have been >> shutdown >> >> The question of how large to make the common Nova-Cinder volume group in >> order >> to enable LVM ephemeral Tempest testing will have to be explored. >> Although, >> given the tiny instance disks used in Nova Tempest tests, the current >> Cinder volume group size may already be adequate. >> >> No new configuration options will be necessary, assuming the volume group >> size >> will not be made configurable. >> >> >> _______________________________________________ >> OpenStack-dev mailing list >> OpenStack-dev@lists.openstack.org >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> >> > > > _______________________________________________ > OpenStack-dev mailing > listOpenStack-dev@lists.openstack.orghttp://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > >
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