[ceph-users] how to improve performance

Christian Balzer chibi at gol.com
Mon Nov 20 15:45:30 PST 2017


On Tue, 21 Nov 2017 10:35:57 +1100 Nigel Williams wrote:

> On 21 November 2017 at 10:07, Christian Balzer <chibi at gol.com> wrote:
> > On Tue, 21 Nov 2017 10:00:28 +1100 Nigel Williams wrote:  
> >> Is there something in the specifications that gives them away as SSHD?
> >>  
> > The 550TB endurance per year for an 8TB drive and the claim of 30% faster
> > IOPS would be a dead giveaway, one thinks.  
> 
> I just found this other answer:
> 
> http://products.wdc.com/library/other/2579-772003.pdf
> 
> Hard-drive manufacturers introduced workload specifications because
> they better model failure rates than MTTF.
>
I've heard that before, alas if you exceed 550TB/year, do you void your
warranty then? 
If so, another thing to keep in mind.
 
> I see the drive has 2MB of NOR-flash for write-caching, what happens
> when this wears out?
> 
Should have been 30x up there of course.

As for NOR, it is supposed to be very durable, but if it fails it
definitely means dead drive and lost data, like with all caches really.


Christian
-- 
Christian Balzer        Network/Systems Engineer                
chibi at gol.com   	Rakuten Communications


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