[linux-lvm] Option to silence "WARNING: Sum of all thin volume sizes exceeds the size of thin pool"

[Zdenek Kabelac]

Dne 19.9.2017 v 10:49 Gionatan Danti napsal(a):
> On 18/09/2017 23:10, matthew patton wrote:
>> If the warnings are not being emitted to STDERR then that needs to be fixed 
>> right off the bat.
> 
> The line with WARNINGs are written on STDERR, at least con recent LVM version.
> 
>> 'lvs -q blah' should squash any warnings.
>> 'lvcreate' frankly shouldn't output anything unless invoked with '-v' 
>> anyway. So therefore '-q' should also squash warnings.
> 
> I'm not sure this is the right approach. I do not expect "-q" to remove *all* 
> warnings, because warnings can be quite important.
> 


There are couple troubles - there are always a 'skilled  X  unskilled' users.
and also there are varying distro maintainers..

We are already facing some troubles when some distributions do make a changes 
to default configuration files which are not really ideal for 'default' users 
(in other words opinions about defaults are different - moreover based on 
wrong blog post from users...)

So we can introduce  i.e.  'novice_user = 1' in lvm.conf  - but it might be 
effectively dropped when package maintainer decides this way lvm2 makes less 
annoying messages around some commands.

But in case of thin-pool it's better to warn-ahead  instead of facing troubles 
later  (as full thin-pool is not going to be pleasant experience...)

So we are looking for some solution which cannot be easily 'hidden' for 
everyone - so we do not end with reports about 'hidden over-provisioning' 
causing system malfunctioning.  Yet it should be 'easy' to bypass it for 
skilled admin.


IMHO the most convenient in my eyes is a usage of some sort of 'envvar'
LVM_SUPPRESS_POOL_WARNINGS....


Since we already use similar logic to bypass i.e.  FD close() warnings
LVM_SUPPRESS_FD_WARNINGS
LVM_SUPPRESS_LOCKING_FAILURE_MESSAGES


Regards

Zdenek