From: Scott Marlowe <scott.marlowe@gmail.com>
To: Stef Telford <stef@ummon.com>
Cc: Greg Smith <gsmith@gregsmith.com>
Cc: Mark Kirkwood <markir@paradise.net.nz>
Cc: Scott Carey <scott@richrelevance.com>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: Raid 10 chunksize
Date: Wed, 1 Apr 2009 10:54:58 -0600
Message-ID: <dcc563d10904010954u582600a9t721fd1a2050a802f@mail.gmail.com> (raw)
In-Reply-To: <49D39AFA.8000700@ummon.com>
References: <C5F14970.3CA1%scott@richrelevance.com>
<49D31E85.8050405@paradise.net.nz>
<49D37CAA.6080100@ummon.com>
<alpine.GSO.2.01.0904011144270.23835@westnet.com>
<49D3932D.3080808@ummon.com>
<dcc563d10904010941r283b7536g383c8daa8b933ce7@mail.gmail.com>
<49D39AFA.8000700@ummon.com>
On Wed, Apr 1, 2009 at 10:48 AM, Stef Telford <stef@ummon.com> wrote:
> Scott Marlowe wrote:
>> On Wed, Apr 1, 2009 at 10:15 AM, Stef Telford <stef@ummon.com> wrote:
>>
>>> I do agree that the benefit is probably from write-caching, but I
>>> think that this is a 'win' as long as you have a UPS or BBU adaptor,
>>> and really, in a prod environment, not having a UPS is .. well. Crazy ?
>>>
>>
>> You do know that UPSes can fail, right? En masse sometimes even.
>>
> Hello Scott,
> Well, the only time the UPS has failed in my memory, was during the
> great Eastern Seaboard power outage of 2003. Lots of fond memories
> running around Toronto with a gas can looking for oil for generator
> power. This said though, anything could happen, the co-lo could be taken
> out by a meteor and then sync on or off makes no difference.
Meteor strike is far less likely than a power surge taking out a UPS.
I saw a whole data center go black when a power conditioner blew out,
taking out the other three power conditioners, both industrial UPSes
and the switch for the diesel generator. And I have friends who have
seen the same type of thing before as well. The data is the most
expensive part of any server.
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To: pgsql-performance@postgresql.org
Cc: scott.marlowe@gmail.com, stef@ummon.com, gsmith@gregsmith.com, markir@paradise.net.nz, scott@richrelevance.com
Subject: Re: Raid 10 chunksize
In-Reply-To: <dcc563d10904010954u582600a9t721fd1a2050a802f@mail.gmail.com>
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