[linux-lvm] Difference between Debian and some other distributions with thin provisioning

[Jan Tulak]

On Sat, Sep 30, 2017 at 7:24 PM, Zdenek Kabelac <zkabelac at redhat.com> wrote:
> Dne 29.9.2017 v 18:42 Jan Tulak napsal(a):
>>
>> Hi guys,
>> I found out this difference and I'm not sure what is the cause. A
>> command for creating a thin LV, which works on Archlinux, Centos and
>> Fedora, fails on Debian and Ubuntu:
>>
>> lvm lvcreate FOOvg1 \
>>      -T \
>>      -l 100%PVS \
>>      -n FOOvg1_thin001 \
>>      /dev/loop0 /dev/loop1 /dev/loop2
>
>
> Hi
>
> This command is not actually creating 'thin'  - only a thin-pool.
> For 'thin' you need to specify -V  --virtualsize.
>
> The usage of -T  is 'smart' flag - telling lvm2 to do 'something'
> thin/thin-pool oriented.
>
> If you want to be 'exact' you can use --type thin  or --type thin-pool
> giving you more errors and requiring user more specific option for passing
> in.
>
Hi,

Ah, thanks for the explanation.


>> Versions seem to be close enough for it not to be a change in LVM
>
>
> Hmm, close enough 111 and 171 ??
>

I would swear I saw different numbers when I wrote it. 117 perhaps?
So, disregard this part of my message. :-)

>
>> behaviour, so I suspect some downstream or configuration changes. All
>> tested distributions were run in their current stable versions, up to
>> date. For example:
>
>
> The original naming convention with pool names was to add the name next to
> VG name.
>
> lvcreate -T -L10 vg/pool
>
> Pool is 'special' type of LV - thus it got this privileged naming and
> standard option --name was normally left for  'thin' when user specifies -V.
>
> Newer version of lvm2 can use  --name with --size specifier for pool name
> when there is no virtual size given as its unique combination.
>
>> Debian:
>> # cat /etc/debian_version
>> 8.9
>> # lvm version
>>    LVM version:     2.02.111(2) (2014-09-01)
>>    Library version: 1.02.90 (2014-09-01) >    Driver version:  4.27.0
>
>
> I'd suggest upgrading your Debian machine....

It is a current Debian 8, so the only thing I can do is to upgrade to
Debian 9 or use a different repository. And indeed, on 9 it works.

Thanks for your answers, I know what the issue is and can now decide
what to do next with it. :-)

Cheers,
Jan