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Re: [linux-lvm] LVM 0.8final for 2.2.15/2.2.16?



> 
> On Wed, 7 Jun 2000, Jan Niehusmann wrote:
> 
> > The snapshot logic simply doesn't know what a filesystem is. It just
> > clones the block device.
> 
> this i knew.. :)
> 
> > So the fs may be in en inconsistent state, if you do the snapshot
> > while some write operation is in progress on the cloned
> > filesystem.
> 
> ok. so the solution is what? a call in the vfs to complete pending
> writes, and hold off on modifying any blocks?

IMHO when creating a snapshot LVM could simply sync all outstanding
buffers for the block device vialog block_fsync() (not sure if this
is already done -- Heinz care to comment?).
This should also take care of pending fs meta information thus
we should get a consistent state.

The question is how atomic this is? Since fsync_dev() currently
does a lock_kernel() is might even be sufficient.


Any reason why this is not suffiecient?

Michael

--
Michael Marxmeier           Marxmeier Software AG
E-Mail: mike msede com      Besenbruchstrasse 9
Phone : +49 202 2431440     42285 Wuppertal, Germany
Fax   : +49 202 2431420     http://www.msede.com/


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