RE: I/O tuning... Allocating spindles to databases

  • From: "Kevin Closson" <kevinc@xxxxxxxxxxxxx>
  • To: "Mercadante, Thomas F (LABOR)" <Thomas.Mercadante@xxxxxxxxxxxxxxxxx>, <jkstill@xxxxxxxxx>, <cmarquez@xxxxxxxxxxxxxxxx>
  • Date: Thu, 15 Sep 2005 12:36:52 -0700

 
absolutely..it is VERY real life to have
an access pattern that completely obliterates
cache...

I can't count how many shops I've known
that completely glue a high end EMC to
the wall and lament the fact that there
is no way to disable the cache...

that was on particular models, I don't
claim to be an EMC expert by any means.

>>>-----Original Message-----
>>>From: Mercadante, Thomas F (LABOR) 
>>>[mailto:Thomas.Mercadante@xxxxxxxxxxxxxxxxx] 
>>>Sent: Thursday, September 15, 2005 12:33 PM
>>>To: kevinc@xxxxxxxxxxxxx; jkstill@xxxxxxxxx; 
>>>cmarquez@xxxxxxxxxxxxxxxx
>>>Cc: bob_murching@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx
>>>Subject: RE: I/O tuning... Allocating spindles to databases
>>>
>>>But would something like this ever really happen in real 
>>>life.  We can all make hardware/software fail once we know 
>>>what its weaknesses are.
>>>
>>>Hell, I can make a database server fail.  Quite simple 
>>>really.  Walk into the server room and flip the breaker.  
>>>Shuts down every time!
>>>
>>>-----Original Message-----
>>>From: oracle-l-bounce@xxxxxxxxxxxxx
>>>[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Kevin Closson
>>>Sent: Thursday, September 15, 2005 3:26 PM
>>>To: jkstill@xxxxxxxxx; cmarquez@xxxxxxxxxxxxxxxx
>>>Cc: bob_murching@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx
>>>Subject: RE: I/O tuning... Allocating spindles to databases
>>>
>>> >>>
>>>>>>It isn't too difficult to write a simulation that will render the 
>>>>>>cache useless.
>>>
>>>actually quite easy. create a file that is 100 fold larger 
>>>than cache and do completely random 4KB transfers.
>>>
>>>smoked
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>>>>
>>>>>>
>>>>>>--
>>>>>>Jared Still
>>>>>>Certifiable Oracle DBA and Part Time Perl Evangelist
>>>>>>11+ years of trying to appear to know what I'm doing.
>>>>>>--
>>>>>>//www.freelists.org/webpage/oracle-l
>>>>>>
>>>--
>>>//www.freelists.org/webpage/oracle-l
>>>
--
//www.freelists.org/webpage/oracle-l

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