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| author | Daniel P. Berrange <berrange@redhat.com> | 2012-03-09 06:01:35 -0500 |
|---|---|---|
| committer | Daniel P. Berrange <berrange@redhat.com> | 2012-03-09 07:59:50 -0500 |
| commit | 2d11e87d2332577170cb983d6f41441bc534cd7e (patch) | |
| tree | ffcd710aceededcc41488ca8b47044239edda0b0 /nova/openstack | |
| parent | 17396f6a08b694b28538462baca582266152da86 (diff) | |
| download | nova-2d11e87d2332577170cb983d6f41441bc534cd7e.tar.gz nova-2d11e87d2332577170cb983d6f41441bc534cd7e.tar.xz nova-2d11e87d2332577170cb983d6f41441bc534cd7e.zip | |
Use cache='none' for all disks
The default QEMU disk cache mode has changed several times in
QEMU's history. This means OpenStack launched VMs have unpredictable
data consistency guarantees and performance characteristics. Using
cache=none bypasses the host page cache by using direct IO. This
ensures:
- Consistent I/O performance for VMs
- Avoids data loss on a host OS crash
- Avoids data corruption of images during migration
Change-Id: I099dac55b8cfa1f0ec5d0e49d1d9ffbe4ae2560d
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Diffstat (limited to 'nova/openstack')
0 files changed, 0 insertions, 0 deletions