Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-12-15 Thread Stefan Ring
On Mon, Nov 13, 2017 at 8:01 PM, Mike Snitzer wrote: > > But feel free to remove the cache for now. Should be as simple as: > lvconvert --uncache VG/CacheLV I did a --splitcache yesterday and ran a scrub again, which completed in 3h. More than the ~2h of the cached version

Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-14 Thread Stefan Ring
On Tue, Nov 14, 2017 at 12:00 PM, Joe Thornber wrote: > I'm not sure what's going on here. Would you mind sending me the > metadata please? Either a cache_dump of it, or a copy of the metadata > dev? Ok, I've copied the device to a file and run cache_dump on it:

Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-14 Thread Stefan Ring
On Tue, Nov 14, 2017 at 12:00 PM, Joe Thornber wrote: > > I'm not sure what's going on here. Would you mind sending me the > metadata please? Either a cache_dump of it, or a copy of the metadata > dev? I'd like to create a cache dump, but I'm not very experienced with this

Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-14 Thread Joe Thornber
On Mon, Nov 13, 2017 at 02:01:11PM -0500, Mike Snitzer wrote: > On Mon, Nov 13 2017 at 12:31pm -0500, > Stefan Ring wrote: > > > On Thu, Nov 9, 2017 at 4:15 PM, Stefan Ring wrote: > > > On Tue, Nov 7, 2017 at 3:41 PM, Joe Thornber

Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-13 Thread Mike Snitzer
On Mon, Nov 13 2017 at 12:31pm -0500, Stefan Ring wrote: > On Thu, Nov 9, 2017 at 4:15 PM, Stefan Ring wrote: > > On Tue, Nov 7, 2017 at 3:41 PM, Joe Thornber wrote: > >> On Fri, Nov 03, 2017 at 07:50:23PM +0100, Stefan Ring wrote:

Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-13 Thread Stefan Ring
On Thu, Nov 9, 2017 at 4:15 PM, Stefan Ring wrote: > On Tue, Nov 7, 2017 at 3:41 PM, Joe Thornber wrote: >> On Fri, Nov 03, 2017 at 07:50:23PM +0100, Stefan Ring wrote: >>> It strikes me as odd that the amount read from the spinning disk is >>> actually

Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-09 Thread Stefan Ring
On Tue, Nov 7, 2017 at 3:41 PM, Joe Thornber wrote: > On Fri, Nov 03, 2017 at 07:50:23PM +0100, Stefan Ring wrote: >> It strikes me as odd that the amount read from the spinning disk is >> actually more than what comes out of the combined device in the end. > > This suggests

Re: [dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-07 Thread Joe Thornber
On Fri, Nov 03, 2017 at 07:50:23PM +0100, Stefan Ring wrote: > It strikes me as odd that the amount read from the spinning disk is > actually more than what comes out of the combined device in the end. This suggests dm-cache is trying to promote too way too much. I'll try and reproduce the issue,

[dm-devel] Significantly dropped dm-cache performance in 4.13 compared to 4.11

2017-11-03 Thread Stefan Ring
Having just upgraded from a 4.11 kernel to a 4.13 one, I see a significantly higher scrub time for a ZFS on Linux (=ZoL) pool that lives on a dm-cache device consisting of a 800 GB partition on one spinning 1TB disk and one partition on an SDD (something between 100 and 200 GB). ZFS scrubbing