Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread John Griffith
On Tue, Oct 21, 2014 at 9:17 AM, Duncan Thomas duncan.tho...@gmail.com wrote: For LVM-thin I believe it is already disabled? It is only really needed on LVM-thick, where the returning zeros behaviour is not done. On 21 October 2014 08:29, Avishay Traeger avis...@stratoscale.com wrote: I

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread Preston L. Bannister
John, As a (new) OpenStack developer, I just discovered the CINDER_SECURE_DELETE option. As an *implicit* default, I entirely approve. Production OpenStack installations should *absolutely* insure there is no information leakage from one instance to the next. As an *explicit* default, I am not

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread Duncan Thomas
On 23 October 2014 08:30, Preston L. Bannister pres...@bannister.us wrote: John, As a (new) OpenStack developer, I just discovered the CINDER_SECURE_DELETE option. As an *implicit* default, I entirely approve. Production OpenStack installations should *absolutely* insure there is no

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread John Griffith
On Thu, Oct 23, 2014 at 1:30 AM, Preston L. Bannister pres...@bannister.us wrote: John, As a (new) OpenStack developer, I just discovered the CINDER_SECURE_DELETE option. As an *implicit* default, I entirely approve. Production OpenStack installations should *absolutely* insure there is

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread John Griffith
On Thu, Oct 23, 2014 at 8:50 AM, John Griffith john.griffi...@gmail.com wrote: On Thu, Oct 23, 2014 at 1:30 AM, Preston L. Bannister pres...@bannister.us wrote: John, As a (new) OpenStack developer, I just discovered the CINDER_SECURE_DELETE option. OHHH... Most importantly, I almost

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread Preston L. Bannister
On Thu, Oct 23, 2014 at 7:51 AM, John Griffith john.griffi...@gmail.com wrote: On Thu, Oct 23, 2014 at 8:50 AM, John Griffith john.griffi...@gmail.com wrote: On Thu, Oct 23, 2014 at 1:30 AM, Preston L. Bannister pres...@bannister.us wrote: John, As a (new) OpenStack developer, I just

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread John Griffith
On Thu, Oct 23, 2014 at 3:44 PM, Preston L. Bannister pres...@bannister.us wrote: On Thu, Oct 23, 2014 at 7:51 AM, John Griffith john.griffi...@gmail.com wrote: On Thu, Oct 23, 2014 at 8:50 AM, John Griffith john.griffi...@gmail.com wrote: On Thu, Oct 23, 2014 at 1:30 AM, Preston L.

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread Preston L. Bannister
On Thu, Oct 23, 2014 at 3:04 PM, John Griffith john.griffi...@gmail.com wrote: The debate about whether to wipe LV's pretty much massively depends on the intelligence of the underlying store. If the lower level storage never returns accidental information ... explicit zeroes are not needed.

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-23 Thread Chris Friesen
On 10/23/2014 04:24 PM, Preston L. Bannister wrote: On Thu, Oct 23, 2014 at 3:04 PM, John Griffith john.griffi...@gmail.com mailto:john.griffi...@gmail.com wrote: The debate about whether to wipe LV's pretty much massively depends on the intelligence of the underlying store. If

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-21 Thread Chris Friesen
On 10/19/2014 09:33 AM, Avishay Traeger wrote: Hi Preston, Replies to some of your cinder-related questions: 1. Creating a snapshot isn't usually an I/O intensive operation. Are you seeing I/O spike or CPU? If you're seeing CPU load, I've seen the CPU usage of cinder-api spike sometimes - not

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-21 Thread Avishay Traeger
I would say that wipe-on-delete is not necessary in most deployments. Most storage backends exhibit the following behavior: 1. Delete volume A that has data on physical sectors 1-10 2. Create new volume B 3. Read from volume B before writing, which happens to map to physical sector 5 - backend

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-21 Thread Duncan Thomas
For LVM-thin I believe it is already disabled? It is only really needed on LVM-thick, where the returning zeros behaviour is not done. On 21 October 2014 08:29, Avishay Traeger avis...@stratoscale.com wrote: I would say that wipe-on-delete is not necessary in most deployments. Most storage

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-19 Thread Avishay Traeger
Hi Preston, Replies to some of your cinder-related questions: 1. Creating a snapshot isn't usually an I/O intensive operation. Are you seeing I/O spike or CPU? If you're seeing CPU load, I've seen the CPU usage of cinder-api spike sometimes - not sure why. 2. The 'dd' processes that you see are

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-19 Thread Preston L. Bannister
Avishay, Thanks for the tip on [cinder.conf] volume_clear. The corresponding option in devstack is CINDER_SECURE_DELETE=False. Also I *may* have been bitten by the related bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1023755 (All I know at this point is the devstack VM became

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-19 Thread Jay Pipes
Hi Preston, some great questions in here. Some comments inline, but tl;dr my answer is yes, we need to be doing a much better job thinking about how I/O intensive operations affect other things running on providers of compute and block storage resources On 10/19/2014 06:41 AM, Preston L.

Re: [openstack-dev] [cinder][nova] Are disk-intensive operations managed ... or not?

2014-10-19 Thread Preston L. Bannister
Jay, Thanks very much for the insight and links. In fact, I have visited *almost* all the places mentioned, prior. Added clarity is good. :) Also, to your earlier comment (to an earlier thread) about backup not really belonging in Nova - in main I agree. The backup API belongs in Nova (as this