I’m fairly sure I saw it as recently as Hammer, definitely Firefly. YMMV.


> On Mar 21, 2017, at 4:09 PM, Gregory Farnum <[email protected]> wrote:
> 
> You shouldn't need to set min_size to 1 in order to heal any more. That was 
> the case a long time ago but it's been several major LTS releases now. :)
> So: just don't ever set min_size to 1.
> -Greg
> On Tue, Mar 21, 2017 at 6:04 PM Anthony D'Atri <[email protected]> wrote:
> >> a min_size of 1 is dangerous though because it means you are 1 hard disk 
> >> failure away from losing the objects within that placement group entirely. 
> >> a min_size of 2 is generally considered the minimum you want but many 
> >> people ignore that advice, some wish they hadn't.
> >
> > I admit I am having difficulty following why this is the case
> 
> I think we have a case of fervently agreeing.
> 
> Setting min_size on a specific pool to 1 to allow PG’s to heal is absolutely 
> a normal thing in certain circumstances, but it’s important to
> 
> 1) Know _exactly_ what you’re doing, to which pool, and why
> 2) Do it very carefully, changing ‘size’ instead of ‘min_size’ on a busy pool 
> with a bunch of PG’s and data can be quite the rude awakening.
> 3) Most importantly, _only_ set it for the minimum time needed, with eyes 
> watching the healing, and set it back immediately after all affected PG’s 
> have peered and healed.
> 
> The danger, which I think is what Wes was getting at, is in leaving it set to 
> 1 all the time, or forgetting to revert it.  THAT is, as we used to say, 
> begging to lose.
> 
> — aad
> 
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