Re: DRBD and Postgres: how to improve the perfomance? - Mailing list pgsql-performance

From Tom Lane
Subject Re: DRBD and Postgres: how to improve the perfomance?
Date
Msg-id 17162.1189400077@sss.pgh.pa.us
Whole thread Raw
In response to Re: DRBD and Postgres: how to improve the perfomance?  (Greg Smith <gsmith@gregsmith.com>)
Responses Re: DRBD and Postgres: how to improve the perfomance?
List pgsql-performance
Greg Smith <gsmith@gregsmith.com> writes:
> On Sat, 8 Sep 2007, Joshua D. Drake wrote:
>> You would have to have lightning handed by God to your server to have a
>> total power failure without proper shutdown in the above scenario.

> Do you live somewhere without thunderstorms?  This is a regular event in
> this part of the world during the summer.  It happened to me once this
> year and once last; lost count for previous ones.  In both of the recent
> cases it's believed the servers were burned from the Ethernet side because
> somewhere in the network was a poor switch that wasn't isolated well
> enough from the grid when the building was hit.  Lightning is tricky that
> way; cable TV and satellite wiring are also weak links that way.

Yeah.  I've lost half a dozen modems of varying generations, a server
motherboard, a TiVo, a couple of VCRs, and miscellaneous other equipment
from strikes near my house --- none closer than a couple blocks away.
I don't really care to think about what would still work after a direct
hit, despite the whole-house surge suppressor at the meter and the local
suppressor on each circuit and the allegedly surge-proof UPSes powering
all the valuable stuff.  I've also moved heavily into wireless local
net to eliminate any direct electrical connections between machines that
are not on the same power circuit (the aforesaid burned motherboard
taught me that particular lesson).  And yet I still fear every time a
thunderstorm passes over.

Then of course there are the *other* risks, such as the place burning to
the ground, or getting drowned by a break in the city reservoir that's
a couple hundred yards up the hill (but at least I needn't worry about
any nearby rivers rising, as I'm well above them).  Or maybe being
burgled by Oracle employees who are specifically after my backup tapes.

If you ain't got a backup plan, you *will* lose data.  Imagining that
there is one perfect technological solution to this problem is the very
fastest way to lose.

            regards, tom lane

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