From owner-freebsd-stable  Mon May  1 18: 1:32 2000
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To: dg@root.com
Cc: Mike Smith <msmith@FreeBSD.ORG>, freebsd-stable@FreeBSD.ORG
Subject: Re: How good is AMI MegaRAID support? 
In-Reply-To: Message from David Greenman <dg@root.com> 
   of "Mon, 01 May 2000 17:37:47 PDT." <200005020037.RAA28837@implode.root.com> 
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Date: Mon, 01 May 2000 18:01:26 -0700
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From: Parag Patel <parag@cgt.com>
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[Re: BSOD and system crashes, UPS and NVRAM]

What if the RAID card's onboard software crashes?  I don't know enough
about these cards to guess at what's more likely - FreeBSD crashing or
the onboard card software crashing.  If they're about equally likely (or
unlikely) then NVRAM vs UPS still seems a wash to me.

Wouldn't any crashes that would toast a filesystem under FBSD care if
the underlying hardware was RAID or a single disk?  Wouldn't it still be
toast either way?

I can see how a NV write-buffer could speed up write performance, but
only if the disk writes are somewhat bursty.  It doesn't seem to be very
different from disks with large onboard caches.  (Which presumably might
still require a UPS to ride out crashes.)

'Course if you're talking M$ OSes, then hardware RAID is clearly better.  :)

(And it's good to hear folks' real-world experiences.  Thanks!)


	-- Parag Patel


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