[linux-lvm] is it right to specify '-l' with all the free PE in VG when creating a thin pool?

[Eric Ren]

On 03/09/2017 07:46 PM, Zdenek Kabelac wrote:
> [snip]
>>
>> while it works when specifying '-l' this way:
>>
>> # lvcreate -l 100%FREE --thinpool thinpool0 vgtest
>>   Logical volume "thinpool0" created.
>>
>> Is this something by design? or something may be wrong?
>> I can replicate this on both:
>
> Hi
>
> Yes this is by DESIGN
>
> When you specify '-l|-L'  you specify size of 'dataLV'  (logical size)
> But then you need some more space for 'metadata' LVs (_tmeta & _pmspare)
>
> -l100%FREE figure this automagically and reduces size a bit to fit in metadata LV.
>
>
> Some 'future' version of lvm2 may support something like '--physicalsize' which will be 'a 
> total size used for every allocation made by command).
Hi Zdenek,

Thanks a lot for your clarification!

Looks some changes to thin-pool feature make it behave differently since a certain version.
It worked on lvm2-2.02.98 (sles12) by specifying '-l' with all the free PE. Anyway, '-l 
100%FREE'
looks more reasonable in such case:)

Regards,
Eric
>
>
> Regards
>
> Zdenek
>
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