Re: SAN evaluation

From: Kurt Franke <>
Date: Wed, 09 Jul 2008 16:58:58 +0200
Message-Id: <>

Hi Tom,

make sure the SAN supports IO-Calls of an appropiate size.

Some years ago we got a SAN from Compaq for cost reduce reasons. This SAN periodically crashed with heavy IO. Some weeks later we got the message from Compaq Support that IO-Calls with more than 64 kB are not supported and ended up with a db_file_multiblock_read_count = 8 while using 8 kB Datablocksize.

Needless to say that we had a lot of IO-Waits with this setting and of course the word perfomance had become a foreign word for our data warehouse system



> We have just begun the process of evaluating a new SAN vendor. We are
> presently developing a list of criteria/requirements/questions for the
> new vendor. So far we have come up with the following:
> 1. What is their I/O speed.
> 2. What kind of SAN replication options do they offer.
> 3. Presently we are using RAID 5. I would like to move to RAID 0+1.
> What do they recommend?
> 4. Does their product have any Oracle related features. For example, I
> know that HP has a SAN developed specifically for an Oracle warehouse.
> Does their product have any bells and whistles for RAC, Streams, etc.
> Has anyone gone through a similar exercise where they had to evaluate a
> SAN vendor? If so, could you share your thoughts with the list?
> Thanks,
> Tom

Received on Wed Jul 09 2008 - 09:58:58 CDT

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