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Re: [linux-lvm] Powerfailure and snapshot consistency



On 3/26/2011 11:07 AM, Stuart D. Gathman wrote:

It is not a bug. Some progress can be made with barriers (similar to
fsync())
that block until all affected blocks are confirmed written on all devices
through all levels of the storage stack (e.g. written to all legs
of a raid1 device). My database does an fsync after each journal batch,
and I think it reasonable to hope that this guarantees that the writes
from the journal batch complete before any subsequent writes. I don't
depend on any other ordering.

Is there some non-destructive diagnostic that can tell you if a running machine can or can't manage write ordering correctly through all of its software and hardware layers?

--
  Les Mikesell
   lesmikesell gmail com


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