Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-08-23 Thread Benoit Depail
On 08/02/17 18:29, Benoit Depail wrote: > On 08/01/2017 11:48 AM, Roger Pau Monné wrote: >> On Fri, Jul 28, 2017 at 04:50:27PM +0200, Benoit Depail wrote: >>> On 07/26/17 00:25, Keith Busch wrote: On Fri, Jul 21, 2017 at 07:07:06PM +0200, Benoit Depail wrote: > On 07/21/17 18:07, Roger Pau

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-08-02 Thread Benoit Depail
On 08/01/2017 11:48 AM, Roger Pau Monné wrote: > On Fri, Jul 28, 2017 at 04:50:27PM +0200, Benoit Depail wrote: >> On 07/26/17 00:25, Keith Busch wrote: >>> On Fri, Jul 21, 2017 at 07:07:06PM +0200, Benoit Depail wrote: On 07/21/17 18:07, Roger Pau Monné wrote: > > Hm, I'm not sure I f

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-08-01 Thread Roger Pau Monné
On Fri, Jul 28, 2017 at 04:50:27PM +0200, Benoit Depail wrote: > On 07/26/17 00:25, Keith Busch wrote: > > On Fri, Jul 21, 2017 at 07:07:06PM +0200, Benoit Depail wrote: > >> On 07/21/17 18:07, Roger Pau Monné wrote: > >>> > >>> Hm, I'm not sure I follow either. AFAIK this problem came from > >>> c

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-28 Thread Benoit Depail
On 07/26/17 00:25, Keith Busch wrote: > On Fri, Jul 21, 2017 at 07:07:06PM +0200, Benoit Depail wrote: >> On 07/21/17 18:07, Roger Pau Monné wrote: >>> >>> Hm, I'm not sure I follow either. AFAIK this problem came from >>> changing the Linux version in the Dom0 (where the backend, blkback is >>> ru

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-25 Thread Keith Busch
On Fri, Jul 21, 2017 at 07:07:06PM +0200, Benoit Depail wrote: > On 07/21/17 18:07, Roger Pau Monné wrote: > > > > Hm, I'm not sure I follow either. AFAIK this problem came from > > changing the Linux version in the Dom0 (where the backend, blkback is > > running), rather than in the DomU right? >

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-21 Thread Benoit Depail
On 07/21/17 18:07, Roger Pau Monné wrote: > On Fri, Jul 21, 2017 at 11:53:33AM -0400, Keith Busch wrote: >> On Fri, Jul 21, 2017 at 12:19:39PM +0200, Benoit Depail wrote: >>> On 07/20/17 19:36, Keith Busch wrote: As a test, could you throttle the xvdb queue's max_sectors_kb? If I fol

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-21 Thread Roger Pau Monné
On Fri, Jul 21, 2017 at 11:53:33AM -0400, Keith Busch wrote: > On Fri, Jul 21, 2017 at 12:19:39PM +0200, Benoit Depail wrote: > > On 07/20/17 19:36, Keith Busch wrote: > > > > > > As a test, could you throttle the xvdb queue's max_sectors_kb? If I > > > followed xen-blkfront correctly, the default

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-21 Thread Keith Busch
On Fri, Jul 21, 2017 at 12:19:39PM +0200, Benoit Depail wrote: > On 07/20/17 19:36, Keith Busch wrote: > > > > As a test, could you throttle the xvdb queue's max_sectors_kb? If I > > followed xen-blkfront correctly, the default should have it set to 44. > > Try setting it to 40. > > > > echo 40

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-21 Thread Benoit Depail
On 07/20/17 19:36, Keith Busch wrote: > On Thu, Jul 20, 2017 at 05:12:33PM +0200, Benoit Depail wrote: >> # Dom0 with a kernel >= 4.4.2, or a custom 4.4.1 including commit >> d2081cfe624b5decaaf68088ca256ed1b140672c >> >> On the dom0: >> # dd if=/dev/zero of=/mnt/d-anb-nab2.img bs=4M count=1280

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-20 Thread Keith Busch
On Thu, Jul 20, 2017 at 05:12:33PM +0200, Benoit Depail wrote: > # Dom0 with a kernel >= 4.4.2, or a custom 4.4.1 including commit > d2081cfe624b5decaaf68088ca256ed1b140672c > > On the dom0: > # dd if=/dev/zero of=/mnt/d-anb-nab2.img bs=4M count=1280 > 1280+0 records in > 1280+0 records out >

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-20 Thread Benoit Depail
On 07/20/17 17:33, Keith Busch wrote: > On Thu, Jul 20, 2017 at 05:12:33PM +0200, Benoit Depail wrote: >> >> The main issue we are seeing is degraded write performance on storage >> devices of Xen PV DomUs, about half (or even a third on our production >> setup where NFS is involved) of what we use

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-20 Thread Keith Busch
On Thu, Jul 20, 2017 at 05:12:33PM +0200, Benoit Depail wrote: > > The main issue we are seeing is degraded write performance on storage > devices of Xen PV DomUs, about half (or even a third on our production > setup where NFS is involved) of what we used to have. Read performance is unchanged?

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-20 Thread Benoit Depail
On 07/20/17 10:52, Roger Pau Monné wrote: > For the sake of the people that I've added, would you mind describing > the issues you are seeing and the tests that you performed? > > Thanks, Roger. > Sure. The main issue we are seeing is degraded write performance on storage devices of Xen PV DomU

Re: [Xen-users] File-based domU - Slow storage write since xen 4.8

2017-07-20 Thread Roger Pau Monné
I'm afraid I'm also not that knowledgeable, so I'm adding the author and the Linux block ml. On Wed, Jul 19, 2017 at 04:25:02PM +0200, Benoit Depail wrote: > Hello, > > On 07/17/17 18:46, Roger Pau Monné wrote: > > There are not a huge amount of changes to blkback, so it would be > > helpful if y