From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Tom Arthurs <tarthurs@jobflash.com>
Cc: erik.myllymaki@aviawest.com, Mark Lewis <mark.lewis@mir3.com>
Cc: Vivek Khera <vivek@khera.org>
Cc: Pgsql performance <pgsql-performance@postgresql.org>
Subject: Re: hardare config question
Date: Mon, 01 May 2006 13:51:55 -0500
Message-ID: <1146509515.22037.26.camel@state.g2switchworks.com> (raw)
In-Reply-To: <445651F1.9070307@jobflash.com>
References: <445236D5.5060509@aviawest.com>
<3DFCE70E-E4BB-40AB-B27F-99E90E8159CA@khera.org>
<1146246441.15712.41.camel@archimedes>
<44564C3F.2040609@aviawest.com>
<445651F1.9070307@jobflash.com>
On Mon, 2006-05-01 at 13:22, Tom Arthurs wrote:
> UPS does not protect against the tech behind the rack unplugging the
> power cable, or an accidental power cycle from exercising the wrong
> switch. :) Both are probably more common causes of failure than a total
> power outage.
>
> Erik Myllymaki wrote:
> > I have been in discussion with 3ware support and after adjusting some
> > settings, the 3ware card in RAID 1 gets better performance than the
> > single drive. I guess this had everything to do with the write (and
> > maybe read?) cache.
> >
> > Of course now i am in a dangerous situation - using volatile write
> > cache without a BBU.
> >
> > If I were to use a UPS to ensure a soft shutdown in the event of power
> > loss, am I somewhat as safe as if I were to purchase a BBU for this
> > RAID card?
Nor does it prevent an electrician from dropping a tiny piece of wire
into a power conditioner, causing a feedback that blows the other two
power conditioners, all three industrial UPSes, and the switch that
allows the Diesal generator to take over.
When that happened to me, I had the only database server in the company
to come back up 100% in tact. You can guess by now I also had the only
database server with battery backed cache...
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To: pgsql-performance@postgresql.org
Cc: smarlowe@g2switchworks.com, tarthurs@jobflash.com, mark.lewis@mir3.com, vivek@khera.org
Subject: Re: hardare config question
In-Reply-To: <1146509515.22037.26.camel@state.g2switchworks.com>
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