Re: [dm-crypt] LUKS NVMe M.2 SSD - save disklayout...

[Matthias Schniedermeyer <ms@citd.de>]

On 04.03.2016 17:05, doark@mail.com wrote:
> On Tue, 1 Mar 2016 19:18:12 Sven Eschenberg wrote:
> > While this is off-topic for this list, if you want to include all data 
> > look at tools like partimage or projects like clonezilla?
> > 
> > If you just want to backup the metadata of all layers in the storage 
> > stack, I'm not aware of any tool for this task.
> > 
> > Am 01.03.2016 um 13:50 schrieb Sumaya1960@gmx.de:
> > > Hi,
> > >
> > > I just wonder, if anyone knows how to save the complete
> > > disklayout/disk partititions for restoring the partitions with the
> > > same layout and UUIDs on another disk.
> > > To establish a disatser recovery plan is the goal of my question.
> > > I am using a NVMe M.2 SSD from Samsung. There you see /dev/nvme0n1 and
> > > it's partitions....
> > >
> > > Any ideas and help would be wonderful!
> > > Thanks to everybody!!!!
> > > Susu
> 
> AFAIK UUIDs are unique to the device and to the partition. You can't
> back them up or restore them to any device. If I'm wrong on this please
> say so, I'm willing to be wrong.
> Also, it seems to me that a backup solution for encrypted data should
> backup and compress the unencrypted data and then reencrypt it. Your free
> to do the backup of the whole encrypted partition though.

I answer in general. UUIDs are things that are stored. So it's usually 
possible to set them to an arbitrary value, for e.g. a previously used 
value.

Altough it doesn't necessarily mean that it is easy to do.
For e.g. for both xfs & ext? filesystems you can change the UUID of the 
filesystem by using the appropriate cli-tool (xfs_admin/tune2fs). So 
it's easy to change the UUIDs for said filesystems.

Or in other words:
Everything in this directory can be manipulated to be how you want them 
to be:
ls -l /dev/disk/by-uuid/

Whereas most things in this directory are derived from things that 
change when you switch devices:
ls -l /dev/disk/by-id/



-- 

Matthias