Re: [dm-crypt] The future of disk encryption with LUKS2

[Arno Wagner <arno@wagner.name>]

Incidentally, this is the way Linux md-RAID checks whether
elements are in sync on RAID assembly. I don't know how 
reliable and often md-RAID updates the counters, but I 
have not run into problems so far.

For the LUKS header, a classic 2-phase commit would
not be a problem. Disks do lie about having flushed
buffers to disk (this world being pretty imperfect, in
particular with regards to its inhabitants), but
with some sensible delays that any header updates need 
anyways, this should be pretty reliable.

Regards,
Arno

On Sat, Feb 06, 2016 at 20:18:02 CET, Sven Eschenberg wrote:
> Okay, I see, for simple updates a counter could indeed be sufficient
> to ensure consistency by bringing the header with lower counter in
> sync with the other one.
> 
> Regards
> 
> -Sven
> 
> Am 06.02.2016 um 20:09 schrieb Michael Kjörling:
> >On 6 Feb 2016 19:56 +0100, from sven@whgl.uni-frankfurt.de (Sven Eschenberg):
> >>Hopefully I did not miss any step and yes, it is not THAT
> >>complicated as there is no concurrency involved, but the
> >>transactions for resizing need to be crafted carefully.
> >
> >I agree, it gets more complicated when resizing a container. I was
> >considering primarily the normal use case of a container that isn't in
> >the process of changing its size.
> >
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-- 
Arno Wagner,     Dr. sc. techn., Dipl. Inform.,    Email: arno@wagner.name
GnuPG: ID: CB5D9718  FP: 12D6 C03B 1B30 33BB 13CF  B774 E35C 5FA1 CB5D 9718
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