Re: asm on san

From: DA Morgan <damorgan_at_psoug.org>
Date: Mon, 15 Dec 2008 12:49:42 -0800
Message-ID: <1229374182.8739@bubbleator.drizzle.com>


hpuxrac wrote:
> On Dec 12, 3:07 pm, DA Morgan <damor..._at_psoug.org> wrote:
>
> snip
>

>> It is more than just when it is in degraded mode. RAID5 has substantial
>> negative impacts on performance all of the time the system is not idle.
>>
>> James Morle, at UKOUG, pointed out that a similar issue exists with the
>> new Solid State drives too making them problematic for small writes.
>>
>> If you shackle a system with RAID5 today, and later need the horsepower,
>> you will find it almost impossible, from a practical standpoint, to get
>> off RAID5. Better to say NO! now than later.
>>
>> If they can't afford the disk ... the data isn't that important.
>>
>> This is not to say backups couldn't be sitting on RAID5. But operational
>> datafiles? redo log files? No way.

>
> Lots of posturing here ... wonder if anyone has ever posted that RAID
> 5 is fine and running on Apple storage hardware is what everyone is
> going to ...
>
> Doesn't smell good from certain contributors to this thread ...

Someone did. That someone also posted the metrics in a White Paper. Someone else, as I clearly recall, argued that the numbers were wrong. Are you planning on falling on one side of the fence or on the fence posts with this one?

-- 
Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org
Received on Mon Dec 15 2008 - 14:49:42 CST

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