26 Jan
2012
26 Jan
'12
2:29 a.m.
I will read this tonight.
I have a meeting with Drobo tomorrow and I think this is the same article on of their guys sent me.
--
Jason T. Slack-Moehrle
On Wednesday, January 25, 2012 at 5:37 PM, aurfalien wrote:
> On Jan 25, 2012, at 4:50 PM, John R Pierce wrote:
>
> > On 01/25/12 4:27 PM, Jason T. Slack-Moehrle wrote:
> > > can you explain to the calculation to determine that 300gb is 2mbps?
> >
> >
> >
> > 300GB (big B for byte) / 30 days / 24 hours/day / 3600 seconds/hour,
> > and
> > I get 0.12MB/second, so multiplying by 10 to get bits allowing for
> > basic
> > protocol overhead, I come up with 1.2Mbit/sec sustained average.
> >
> >
> > racking 2 PiB (or 2048TiB) of nearline grade storage will require
> > about
> > 1000 3.5" 3TB drives, allowing for a reasonable raid level and
> > suitable
> > number of hotspares. If its frequently updated transactional
> > database
> > storage, I'd want to use raid10. Using somethign like the Supermicro
> > 847 chassis, you can get 36 drives plus a server in 4U, and draw about
> > 700 watts actual in use.... I estimate you'll want about 28 of these
> > servers, which will take two full racks and draw about 20KW, or 180
> > amps
> > off 120V household circuits (realistically, you'll need 208V for this
> > many servers). You'll also need about 10-15KW worth of air
> > conditioning equipment to deal with the generated 68000 BTUs of heat.
> > HVAC will push your power usage up to the 30-40kW range, or 2500
> > KWH/month, at $0.20/KWH typical residential power usage, you're
> > looking
> > at a $5000/month power bill, give or take.
> >
> > those 28 SuperMicro servers will cost about $200,000 for the 1000 3TB
> > enterprise nearline disks, plus another $200,000 or so for reasonably
> > well configured servers. 20KVA of redundant UPS and 70000 BTU worth
> > of
> > computer room A/C will add a good chunk more $$$$ to this.
> >
> > are you serious?
>
> Nice analysis.
>
> Yea the heat footprint alone will require some good AC. I'm open
> minded and am intrigued on who this will be pulled off but still,
> sounds crazy and not too well thought out.
>
> I do like the not for profit spin which helps the cause out.
>
> A quick search found this;
>
> http://bioteam.net/2011/08/why-you-should-never-build-a-backblaze-pod/
>
> Basically its a sort of why not to use a backBlaze but we sort did ...
>
> - aurf
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