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 <mailto:daniel.ge...@jhuapl.edu>> wrote:


    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

    Suggestions on architecture, implementation and the blueprint in
    general are very


    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
    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

     * rename the Cinder volume group to something generic, e.g.,

     * 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

     * cleanup the volume group in unstack.sh after the services have been

    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.
    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 mailing list

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature

OpenStack-dev mailing list

Reply via email to