Re: Write cache for a SAN

From: Svetoslav Gyurov <>
Date: Tue, 04 Nov 2008 09:37:48 +0200
Message-ID: <>


Hi Jared,

Probably you are right. Service engineers or new folks are sent to the customer site and they not always realize the importance of the customers data. In particular the EVA is disabling the write cache of the controller when the batteries go bad so in this case you need to hope the service engineer is not changing the batteries of the good one controller (although the bad battery has a warning led lighted on it).


Jared Still wrote:
On Mon, Nov 3, 2008 at 7:19 AM, Freeman, Donald <> wrote:
We don't disable it.  The SAN manufacturers have made this as bullet proof as possible. 

Guess what happens when the storage vendor sends out a tech to replace batteries
(the batteries that ensure the write cache stays put), and the tech can't be bothered
to follow instructions?

What do you think might happen to the write cache?

I'm not saying that the write cache should be disabled, but you need to ensure that
the folks that maintain the HW actually know what they are doing.

Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

-- Received on Tue Nov 04 2008 - 01:37:48 CST

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