Message-ID: <47DCB347.2060706@davidnewall.com>
Date: Sun, 16 Mar 2008 16:12:31 +1030
From: David Newall <davidn@davidnewall.com>
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To: Daniel Phillips <phillips@phunq.net>
CC: Willy Tarreau <w@1wt.eu>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
       linux-kernel@vger.kernel.org
Subject: Re: [ANNOUNCE] Ramback: faster than a speeding bullet
References: <200803092346.17556.phillips@phunq.net> <200803131214.40321.phillips@phunq.net> <20080315205950.GA13012@1wt.eu> <200803151417.13899.phillips@phunq.net>
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Daniel Phillips wrote:
>> Also, please note that the problem here is not related to the number of
>> nines of availability. This number only counts the ratio between uptime
>> and downtime. We're more facing a problem of MTBF, where the consequences
>> of a failure are hard to predict.
>>     
>
> That is why I keep recommending that a ramback setup be replicated or
> mirrored, which people in this thread keep glossing over.  When
> replicated or mirrored, you still get the microsecond-level transaction
> times, and you get the safety too.

Do you mean it should be replicated with a second ramback?  That would
be pretty pointless, since all failure modes would affect both.  It's
not like one ramback will survive a crash when the other doesn't.
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