From xyao at cse.unl.edu  Wed Feb 22 14:56:42 2006
From: xyao at cse.unl.edu (Xiaoyu Yao)
Date: Wed, 22 Feb 2006 13:56:42 -0600
Subject: [Disksim-users] Ask help on cmd line parameter overrides in disksim
	3.0 ?
Message-ID: <001301c637ea$1d68f310$6400a8c0@Safari>

Hi, all

Any one has experience with disksim 3.0 command line parameter overrides? I
try to override the disksim synthetic generator parameters through command
line override interface to do a sensitivity study on RAID performance.  

To be specifically, I want to vary the mean value of "General inter-arrival
times" from 10ms to 100ms.  

 I know the manual has a simple example to illustrate how to adjust the disk
schedule algorithm. But the general inter-arrival time is defined as a tuple
in the parameter file. ( General inter-arrival times  = [ exponential, 0.0,
50.0  ],) I tried the following command but it does not work. 

$ ../src/disksim raid1.parv out ascii 0 1 "gen0" "General inter-arrival
times" 10; 

The following is the generator configuration. 

 disksim_synthio Synthio {
   Number of I/O requests to generate =  50000,
   Maximum time of trace generated  =  9999999.0,
   System call/return with each request =  0,
   Think time from call to request =  0.0,
   Think time from request to return =  0.0,
   Generators = [
     disksim_synthgen gen0 { # generator 0 
       Storage capacity per device  =  16448064,
       devices = [ disk3 ], 
       Blocking factor =  8,
       Probability of sequential access =  0.4,
       Probability of local access =  0,
       Probability of read access =  1,
       Probability of time-critical request =  0,
       Probability of time-limited request =  0,
       Time-limited think times  = [ normal, 30.0, 100.0  ],
       General inter-arrival times  = [ exponential, 0.0, 50.0  ],
       Sequential inter-arrival times  = [ exponential, 0.0, 10.0  ],
       Local inter-arrival times  = [ exponential, 0.0, 10.0  ],
       Local distances  = [ normal, 0.0, 40000.0  ],
       Sizes  = [ exponential, 0.0, 64.0  ]
     } # end of generator 0
   ] # end of generator list 
} # end of synthetic workload spec

I think there should be some methods to override this type of parameters.
Any help will be appreciated!

Xiaoyu





From xyao at cse.unl.edu  Thu Feb 23 17:29:00 2006
From: xyao at cse.unl.edu (Xiaoyu Yao)
Date: Thu, 23 Feb 2006 16:29:00 -0600
Subject: [Disksim-users] Ask help on cmd line parameter overrides in
	disksim 3.0 ?
In-Reply-To: <4fc1e0430602221330l30c43d6bx6c370db007e6196e@mail.gmail.com>
Message-ID: <001701c638c8$8e346190$6400a8c0@Safari>

Hi, John

Maybe we can do  a slight modification of the syntax by assigning each
parameter in the list an explicit name. Therefore, if we want to change the
mean of General inter-arrival times, we can use "General inter-arrival
times: mean" to override it.

For example, we change the syntax of

 General inter-arrival times  = [ exponential, 0.0, 50.0  ],

to

General inter-arrival times = 
{
	type = "exponential",
	base = 0.0,
	mean = 50.0
}

Xiaoyu

-----Original Message-----
From: jsbucy at gmail.com [mailto:jsbucy at gmail.com] On Behalf Of John Bucy
Sent: Wednesday, February 22, 2006 3:30 PM
To: Xiaoyu Yao
Cc: disksim-users at ece.cmu.edu
Subject: Re: [Disksim-users] Ask help on cmd line parameter overrides in
disksim 3.0 ?

On 2/22/06, Xiaoyu Yao <xyao at cse.unl.edu> wrote:
> Hi, all
>
> Any one has experience with disksim 3.0 command line parameter 
> overrides? I try to override the disksim synthetic generator 
> parameters through command line override interface to do a sensitivity
study on RAID performance.
>
> To be specifically, I want to vary the mean value of "General 
> inter-arrival times" from 10ms to 100ms.

This is a known shortcoming of the syntax of the overrides;  you can't
"reach into" a list using that mechanism currently.  I know this is a pain
point for many users so we'll see about getting it fixed before we release a
new version in the coming weeks/months.

In the meantime, I'm afraid you'll have to write some perl or something to
edit the parameter file and run disksim.



john