Re: New dirty tricks in Red Hat 5.x

From: joel garry <>
Date: Wed, 20 May 2009 09:35:40 -0700 (PDT)
Message-ID: <>

On May 19, 11:28 pm, Mladen Gogala <> wrote:
> 1) CFS and ionice

>    Kernels newer then 2.6.13 come with the "CFS" (Completely Fair
>    Scheduler) I/O scheduler which can assign I/O priorities to processes.
>    ionice -c 1 -n 0 -p `pgrep -f lgwr` will assign the highest real-time
>    priority to the oracle log writer. If two or more processes have
>    something to write to the same disk, log writer will always get there
>    first. The same thing can be done with DBWR as well. There isn't much
>    sense in  doing that when ASM is involved, as ASM usually has its own
>    piece of disk for exclusive use. This usually helps on a busy file
>    system single instance databases, where file systems are used for
>    other apps as well. Classic example is having both Apache and Oracle on
>    the same system. Those two pieces of software have completely different
>    I/O usage patterns and you may decide to give one of them higher
>    priority than the other one. It doesn't necessarily have to be Oracle.

Not sure I quite understand this own piece of disk thing, won't it be mooted by controller bottlenecks?

Thanks for sharing good info, and congrats on your son. My 13-year- old just won a ribbon in a math competition, first time anyone placed for his obscure magnet school, the two seconds after the announcement of an entire gymnasium of mostly expensive private and rich area public schools looking around in confusion going "say what school?" was just priceless. He was especially shocked, since he hasn't even taken trig yet, and was moved into this particular part of the competition at the last minute.


-- is bogus.
Meanwhile, California voters pulled another proposition 13 style tax
revolt in a special election yesterday, soundly defeating even the
possibility of partly fixing $23B in projected budget deficits,
because, like Barbie said, math is hard.
Received on Wed May 20 2009 - 11:35:40 CDT

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