[linux-lvm] LVM PV UUID problem

[Digimer]

On 2020-10-09 10:43 a.m., Zdenek Kabelac wrote:
> Dne 09. 10. 20 v 15:12 Digimer napsal(a):
>> Hi all,
>>
>>    I'm storing LVM information in a postgres database, and wanted to use
>> the UUID from the PVs / VGs / LVs as the UUIDs in the database. I
>> noticed when I tried to do this that postgres complained that the UUID
>> was not valid. I checked with an online UUID validator
>> (https://www.freecodeformat.com/validate-uuid-guid.php) and it also
>> reported as invalid.
>>
>> Example;
>>
>> ====
>> # pvdisplay | grep UUID
>>    PV UUID               jLkli2-dEXx-5Y8n-pYlw-nCcy-9dFL-3B6jU3
>> ====
>>
>>    Is this a known issue?
>>
> 
> Hi
> 
> At the time of lvm2 devel I believe UUID was just a unique identifier,
> later some effort to standardize it came in.
> 
> But really you should NOT be using basically internal unique identifiers
> in your DB - this are internal to DM/LVM work and might be changed at
> any time to something else.
> 
> User is supposed to use  'vgname' & 'lvname'  - so there you can put those
> valid UUID sequences - although human readable strings are always nicer ;)
> 
> Zdenek

The trick is that VG and LV names can change, so I wanted to use the
(so-called) UUID as a way to keep track of a given item through name
changes.

I suppose I'll have to rework to use the internal "UUIDs" as more like
serial numbers instead...

-- 
Digimer
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