Re: [dm-devel] poor thin performance, relative to thick

2016-07-15 Thread Mike Snitzer
On Thu, Jul 14 2016 at 12:21am -0400, Jon Bernard wrote: > Do you have any intuition on where to start looking? Joe asked me a very basic/obvious question: is block zeroing enabled? (block zeroing is enabled by default -- you have to know to disable it) If zeroing wasn't

Re: [dm-devel] poor thin performance, relative to thick

2016-07-14 Thread Mike Snitzer
On Thu, Jul 14 2016 at 12:21am -0400, Jon Bernard wrote: > * Mike Snitzer wrote: > > On Mon, Jul 11 2016 at 4:44pm -0400, > > Jon Bernard wrote: > > > > > Greetings, > > > > > > I have recently noticed a large difference in

Re: [dm-devel] poor thin performance, relative to thick

2016-07-13 Thread Jon Bernard
* Mike Snitzer wrote: > On Mon, Jul 11 2016 at 4:44pm -0400, > Jon Bernard wrote: > > > Greetings, > > > > I have recently noticed a large difference in performance between thick > > and thin LVM volumes and I'm trying to understand why that it the

Re: [dm-devel] poor thin performance, relative to thick

2016-07-13 Thread Mike Snitzer
On Tue, Jul 12 2016 at 11:29pm -0400, Jon Bernard wrote: > * Jack Wang wrote: > > 2016-07-11 22:44 GMT+02:00 Jon Bernard : > > > Greetings, > > > > > > I have recently noticed a large difference in performance between thick >

Re: [dm-devel] poor thin performance, relative to thick

2016-07-12 Thread Jon Bernard
* Zdenek Kabelac wrote: > Dne 11.7.2016 v 22:44 Jon Bernard napsal(a): > > Greetings, > > > > I have recently noticed a large difference in performance between thick > > and thin LVM volumes and I'm trying to understand why that it the case. > > > > In summary, for the same

Re: [dm-devel] poor thin performance, relative to thick

2016-07-12 Thread Jon Bernard
* Jack Wang wrote: > 2016-07-11 22:44 GMT+02:00 Jon Bernard : > > Greetings, > > > > I have recently noticed a large difference in performance between thick > > and thin LVM volumes and I'm trying to understand why that it the case. > > > > In

Re: [dm-devel] poor thin performance, relative to thick

2016-07-12 Thread Mike Snitzer
On Mon, Jul 11 2016 at 4:44pm -0400, Jon Bernard wrote: > Greetings, > > I have recently noticed a large difference in performance between thick > and thin LVM volumes and I'm trying to understand why that it the case. > > In summary, for the same FIO test (attached), I'm

Re: [dm-devel] poor thin performance, relative to thick

2016-07-12 Thread Zdenek Kabelac
Dne 11.7.2016 v 22:44 Jon Bernard napsal(a): Greetings, I have recently noticed a large difference in performance between thick and thin LVM volumes and I'm trying to understand why that it the case. In summary, for the same FIO test (attached), I'm seeing 560k iops on a thick volume vs. 200k