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

[Sven Eschenberg <sven@whgl.uni-frankfurt.de>]

Am 04.03.2016 um 23:05 schrieb doark@mail.com:
> 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.

The very purpose of UUIDs is to be UNIQUE in every respect. It is 
however no problem to i.e. backup metadata including UUIDs and use it 
for another disk at a later time, i.e. on a replacement disk after a 
failure. (Depends of the setup used to a certain extent)

A mirror (i.e.) will have the very same FS UUID on both legs 
(obviously). If the mirror falls apart, then the fs driver will usually 
prevent you from mounting both copies of the FS, as the UUIDs are 
identical and a double mounts ask for major wreckage. But, as you can 
observe, the context defines uniqueness.

>
> Sincerely, David
>

Regards

-Sven