[lvm-devel] [PATCH V2 0/2] Add thin lv and thin pool creation support

[Tony Asleson]

On 02/01/2013 12:08 AM, M. Mohan Kumar wrote:
> Tony Asleson <tasleson at redhat.com> writes:
>> One option would be to change the type to a signed integer and change
>> the meaning from number of blocks free to percentage free and then treat
>> -1 as pick a sane default.  Thus 0 would be no events and 30 would
>> indicate when 30% blocks free is remaining to generate an event.  We
>> could also use an unsigned value and use 100 as please pick a sane
>> default as this value and values close to it really wouldn't make much
>> sense.
> 
> IMHO specifying the % in threshold is a good idea. You suggest to assume some
> default threshold for newly created thin pool if user is not passing
> anything. May be we can document this in lvm2app.h mentioning if '0'
> passed as percentage it will be treated as the default thresold and 100%
> means no event will be generated. What do you think about this policy?

This would be fine too.  As long as we clearly document what the value
represents and what the special values which denote disable and select
default we should be good.

Do we know what a reasonable threshold value should be?

Thanks,
Tony