Re: Oracle and Raid setup

From: VC <boston103_at_hotmail.com>
Date: Sun, 12 Jun 2005 19:34:44 -0400
Message-ID: <VqudnZ9S56AOWzHfRVn-tg@comcast.com>

Hi,

<xhoster_at_gmail.com> wrote in message
news:20050612153921.585$Yk_at_newsreader.com...

> "VC" <boston103_at_hotmail.com> wrote:

>> Hi,
>>
>> <xhoster_at_gmail.com> wrote in message
>> news:20050609141630.752$66_at_newsreader.com...
>> > Frank van Bortel <frank.van.bortel_at_gmail.com> wrote:
>> [... skipped ...]
>>
>> >> Why would a mirrored write be slower for writes? OK, as slow
>> >> as the slowest disk, but those differences can (should!) only
>> >> be marginal.
>> >
>> > If each write takes a random amount of time uniformly distributed
>> > between 0 and 1 (in whatever units of time would make sense), then the
>> > average wait for one write is 0.5, while the average wait for slower of
>> > two
>> > writes is 0.6667.
>>
>> I wonder how you arrived at the number (0.6667)...
>
> Probability and calculus.

 [..skipped..]

Of course, you are right. I missed the point that in your model it's the response time that's uniformly distributed between 0 and 1. Received on Sun Jun 12 2005 - 18:34:44 CDT