Re: asm on san

From: DA Morgan <>
Date: Mon, 15 Dec 2008 12:49:42 -0800
Message-ID: <>

hpuxrac wrote:
> On Dec 12, 3:07 pm, DA Morgan <> 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 (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Mon Dec 15 2008 - 14:49:42 CST

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