Messages in this thread | | | Date | Wed, 15 Apr 2009 14:46:01 +0200 | From | Jens Axboe <> | Subject | Re: Out-of-order writing by disk drives |
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On Tue, Apr 14 2009, Chris Mason wrote: > On Tue, 2009-04-14 at 20:50 +0200, Andi Kleen wrote: > > On Tue, Apr 14, 2009 at 10:09:48PM +0400, Michael Tokarev wrote: > > > Andi Kleen wrote: > > > [] > > > >Where I see it as a problem is with virtualization; LVM seems to be the > > > >most sane way to manage file systems for lots of VMs and you likely > > > >want barriers there too. > > > > > > Virtualisation is the best fit for partitionable raid1 arrays. > > > It is, in fact, what we have here -- I tested LVM but rejected > > > it because of this very issue - it does not support barriers. > > > > It does now as of 2.6.29, as long as you only have a single > > underlying device and use dm linear. > > Eric Sandeen noticed this is actually still broken: > > http://lkml.org/lkml/2009/3/23/360
Alasdair promised to push the remaining barrier bits for 2.6.30, so hopefully it should all be in working order Real Soon Now.
-- Jens Axboe
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