yahoo-eng-team team mailing list archive

[Sylvain Bauza <sbauza@xxxxxxx>]

Honestly, I wonder if LVM sparse LVs worked. Looks like we don't have
any functiona tests for that (just the unittests) and we merged the
blueprint by 5 years ago.

If you also see that comment in
https://github.com/openstack/nova/blob/c1eb6f0/nova/virt/libvirt/imagebackend.py#L688-L689
looks like the sparse LVs should be deprecated.

FWIW, that deprecation comment was also merged 5 years ago, which means
we don't really support that now.

Given also now we have Cinder volumes, it's possible to ask Cinder to
have thin provisioning instead of using LVM sparse LVs by using that
document https://docs.openstack.org/cinder/latest/admin/blockstorage-
over-subscription.html

So, given the above, setting that bug as Wontfix and we will be trying
to really deprecate sparse LVs by the next release.

** Changed in: nova
       Status: New => Won't Fix

-- 
You received this bug notification because you are a member of Yahoo!
Engineering Team, which is subscribed to OpenStack Compute (nova).
https://bugs.launchpad.net/bugs/1740025

Title:
  LVM Sparse Volumes broken

Status in OpenStack Compute (nova):
  Won't Fix

Bug description:
  Description
  ===========
  Instance creation with LVM Sparse volumes as root disk is broken.

  Steps to reproduce
  ==================
  Configure nova-compute to use LVM with sparse volumes:
  Add to /etc/nova/nova.conf and restart nova-compute:
  [libvirt]
  images_type=lvm
  images_volume_group=<volume-group>
  sparse_logical_volumes=true

  Schedule an instance with an image that is bigger than 64 MB.

  Expected result
  ===============
  Instance is created successfully.

  Actual result
  =============
  Error while writing the image to the logical volume because the Image is bigger than the preallocated 64 MB volume.

  Please see attached log file.

  Environment
  ===========
  OpenStack Release: Pike
  Nova Version: 16.0.3 (CentOS 7 RPM)

  Hypervisor Type: Libvirt + KVM

  Storage Type: LVM (Sparse)

  Networking Type (not applicable): Neutron with LinuxBridge

  References
  ==========

  This bug was already reported to Mirantis OpenStack:
  https://bugs.launchpad.net/mos/+bug/1591084

To manage notifications about this bug go to:
https://bugs.launchpad.net/nova/+bug/1740025/+subscriptions