Re: asm on san

From: joel garry <>
Date: Thu, 11 Dec 2008 13:16:01 -0800 (PST)
Message-ID: <>

On Dec 11, 6:32 am, Mladen Gogala <> wrote:
> helter skelter wrote:
> > Hi,
> > I'm preparing to test some configurations on san storage array. I would
> > like to find out what will be better in my environment: raid1+0 or
> > raid5. Other thing is what size of segment size should be configured on
> > storage array. For example, I've got 5 disks in RAID5, so if ASM default
> > stripe size for datafiles is 1MB, so segment size on strage shouls be
> > 256KB to hit all drives, am I right?
> > What tools are You recommend to do tests like this: sequentail/sequence
> > reads etc?  thanks
> > oracle 10gr2, rhel5
> RAID 5 is not good for databases, period. Not for data files, especially not
> for the log files, you can only use RAID 5 partition for log_archive_dest_25
> If your boss told you to evaluate RAID 5, it is very likely that he wants to
> save some money in the wrong place and will buy you RAID 5, no matter what
> your findings are. Moan Isnogood has a great site at
> The abbreviation "BAARF" stands for "Battle Against Any Raid Five". Your
> company is probably doomed and will not make it through the recession. Have
> a nice day.
> --http://

While I agree with you and Dan, having an interesting member number bitwise on baarf and general agreement on the principles, I have to admit that it works for my employer, who not only is not doomed but keeps me busy with expansion projects. Business needs uber alles and all that. The only time it is a problem is when it is operating in degraded mode or some rare thing overwhelms the buffering. The more usual case is akin to a mostly empty municiple bus, plenty of room for quite a bit more riders. I'd like to take the thanks for that, but really it's just a reasonable configuration for what it does (ERP/MRP OLTP, mostly). If I had to choose between Itanium hp-ux RAID-5 and Itanium Windows RAID-10, I wouldn't pick the Windows.


-- is bogus.
Big packet must get through!
Received on Thu Dec 11 2008 - 15:16:01 CST

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