when deleting volume in lvm, dd disk i/o performance issue

Registered by inhye.park on 2013-10-29

I had in trouble in cinder volume deleting.
I am developing for supporting big data storage such as hadoop in lvm .

it use as a full disk io for deleting of cinder lvm volume because of dd
The high disk I/O affects the other hadoop instance on same host.

So when i delete the volume, i added disk io schduler, ionice

Used in the following way.

     def _copy_volume(self, srcstr, deststr, size_in_g):
- self._execute('dd', 'if=%s' % srcstr, 'of=%s' % deststr,
+ self._execute('ionice', '-c3', 'dd', 'iflag=direct', 'oflag=direct',
+ 'if=%s' % srcstr, 'of=%s' % deststr,
                       'count=%d' % (size_in_g * 1024), 'bs=1M',
                       run_as_root=True)

Blueprint information

Status:
Complete
Approver:
John Griffith
Priority:
Low
Drafter:
None
Direction:
Needs approval
Assignee:
inhye.park
Definition:
Obsolete
Series goal:
Accepted for future
Implementation:
Started
Milestone target:
milestone icon next
Started by
inhye.park on 2013-10-29
Completed by
Sean McGinnis on 2015-10-08

Related branches

Sprints

Whiteboard

cosmos : Hello. I want to know about that. Is this blueprint approved? Then. I will upload Source Code. Thank you.

EricH> If pursued, this needs to be a config option that defaults to the current behavior. Doing this by default is rather risky because it could make volume delete operations run for a very long time on a busy system. I would advise switching to ThinLVM if possible, rather than implementing this.

Gerrit topic: https://review.openstack.org/#q,topic:bp/when-deleting-volume-dd-performance,n,z

Addressed by: https://review.openstack.org/74810
    Add optional ionice to volume clearing process

By looking into the patch https://review.openstack.org/74810, it has been merged in 2014-04-28. I think it could flag as implement.
---- ling-yun 2014-09-06

Seems to be implemented in Kilo. Related bp: https://blueprints.launchpad.net/cinder/+spec/limit-volume-copy-bps-per-backend -- Eric Harney

(?)

Work Items

This blueprint contains Public information 
Everyone can see this information.

Subscribers

No subscribers.