Messages in this thread | | | Date | Sat, 23 Mar 2013 03:48:03 +0000 | From | Alasdair G Kergon <> | Subject | Re: [dm-devel] dm: dm-cache fails to write the cache device in writethrough mode |
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On Fri, Mar 22, 2013 at 11:27:16PM -0400, Mike Snitzer wrote: > So the big difference is the thinp-test-suite uses intermediate linear > DM layers above the slower sd device (spindle/data) -- whereas in your > setup the origin device is direct to sd (8:0).
I would think the difference is because DM issues (edited) copies of incoming bios to the layers underneath, so changes don't propagate back up.
Darrick: if you retest with a dm linear device, does the problem go away?
Alasdair
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