[tahoe-dev] Volunteer Grid 2 hits a milestone

[Shawn Willden]

On Fri, Apr 6, 2012 at 4:17 PM, Olivier Schwander <
olivier.schwander at chadok.info> wrote:

> Nice work on the vg2.
>
> Le 06 Apr 2012 07:58, Shawn Willden a écrit:
> > we currently have just over 9 TB available storage space, right around
> > 6 TB used, and we're uploading 140 GB per day.
>
> I'm a bit curious: what are the common use cases for this ? It should be
> interesting to have some statistics/examples/success story on the
> website.
>

I think most of us are using it for backup.  That was my goal when I
started "encouraging" (cajoling?) the early members to establish high
uptime, high capacity and wide node distribution requirements -- to create
a virtually indestructible Internet-based backup solution.


> > Next goal:  32 nodes highly-reliable nodes.
>
> What are the advice or requirements to reach your 95% uptime goal ? I
> guess the hardware is not really a problem but the connection must
> matter a lot. Are you using ADSL, optic fiber, high-end connection in a
> datacenter ? I don't have any idea of the availability a home ISP may
> provide.


95% really isn't that high.  Over the course of a year, for example, you
can have over 18 days of downtime and still reach 95%.  That's 36 hours of
downtime per month.  In practice, most of our nodes exceed the availability
requirements by a large margin, even though many of them are on home ADSL
or cable modem connections.  If your home ISP service were down a day and a
half every month, you'd change ISPs.  Well, I would, anyway.

The uptime requirement is really more of a question of attitude.  We want
members of the grid to go into it with the attitude that they have a
responsibility to keep their nodes up and running 100% of the time.  The
stated 95% goal is really just an admission that we understand perfection
is impossible.  It also provides a baseline we can use for statistical
calculations used to estimate failure probabilities and derive reasonable
erasure-coding parameters.

-- 
Shawn
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