Bug 842136

Summary: [nova][RFE][Resize|Migrate][preformance] avoid ssh/scp on shared nova-lib dir.
Product: Red Hat OpenStack Reporter: David Naori <dnaori>
Component: openstack-novaAssignee: Brent Eagles <beagles>
Status: CLOSED ERRATA QA Contact: Yogev Rabl <yrabl>
Severity: medium Docs Contact:
Priority: medium    
Version: 1.0 (Essex)CC: abaron, apevec, beagles, jkt, markmc, mlopes, ndipanov, pbrady, sgordon
Target Milestone: Upstream M3Keywords: CodeChange, FutureFeature, Improvement
Target Release: 4.0   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: storage
Fixed In Version: openstack-nova-2013.2-0.8.b2.el6ost Doc Type: Enhancement
Doc Text:
With this update, migration operations will not attempt to copy data when the specified source and destination are the same filesystem location. This is due to the consideration that recopying the data would be inefficient and may risk corrupting the file.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2013-12-19 23:53:14 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 975499    

Description David Naori 2012-07-22 13:41:36 UTC 
Description of problem:
nova should avoid ssh/scp when Resizing/Migrating to remote host with shared nova-lib directory

it can use check_shared_storage_test_file to indicate if its on shared storage or not and act differently.

log:
ssh 10.35.77.4 mkdir -p /mnt/nova-lib/instances/instance-00000174 from (pid=14823) execute /
usr/lib/python2.6/site-packages/nova/utils.py:220

scp /mnt/nova-lib/instances/instance-00000174_resize/disk_rbase 10.35.77.4:/mnt/nova-lib/instances/instance-00000174/disk from (pid=14823) execute /usr/lib/python2.6/site-packages/nova/utils.py:220

Version-Release number of selected component (if applicable):
openstack-nova-2012.1.1-4.el6.noarch
Comment 1 Pádraig Brady 2012-07-23 09:26:21 UTC 
Yep should look into this in detail.
rsync might mitigate somewhat, though that might be foiled by the
mv ... ..._resize operation done on the directory.
Comment 2 Nikola Dipanov 2012-12-13 15:54:37 UTC 
Moving this to Grizzly as we have
Comment 3 Nikola Dipanov 2012-12-13 15:55:33 UTC 
... shipped Folsom and we won't be adding any features to it.
Comment 5 Brent Eagles 2013-09-05 20:29:06 UTC 
It looks like the fix landed in havana-1 and was backported to Grizzly (d34d4cacf7b20f72c67f7873dcf2c372abc60ecd).

Change-Id: Ie9decedd373c000211c171df64e1e96fe78e5081
Comment 11 errata-xmlrpc 2013-12-19 23:53:14 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHEA-2013-1859.html