Re: [MooseFS-Users] Fwd: CHUNKS_LOOP_MAX_CPS clarification

[Marco M. <mar...@gm...>]

On 05/11/2018 09:29 AM, Gandalf Corvotempesta wrote:
> Il giorno ven 11 mag 2018 alle ore 11:21 Marco Milano <mar...@gm...>
> ha scritto:
>> The scenario you describe is only likely to happen if you have only two
> copies
>> and lots of unaccessed data. If you keep 3 or 4 or more copies it is not
> likely
>> to happen.
> 
> If cluster is used as backup or archive, replica 3 or EC 8,2 would be
> overkill and useless.
> It's only a waste of space and resources.

And why would EC 8+2 be overkill ? I am assuming that you are at least using
2 copies now, which means that if you had 1PB of real data, you will need 2PB
of raw disk space. If you use EC 8+2, you will need only 1.25PB of raw disk space
saving you 0.75PB of raw disk space and giving you the equivalent of 3 copies.
You pay less, you get more.  :-)

How is that in your own words "waste of space and resources" ??

-- Marco


> 
>> If you are losing sleep over your data currently, you can write a very
> simple script
>> that will read your entire filesystem in a loop.
> 
> Sure. But I think that a software-defined-storage should take care of data
> consistency by itself
> and not rely on external scripts.
> 
> Additionally, MFS already has a scrub feature, but on huge clusters it's
> useless, a scrub won't
> finish in useful time.
>