Right size of RAM and NVRAM for Dynamips devices?

Unanswered Question
Aug 13th, 2008

I have two Dynamips labs. One has 8 7206 and the other has 8 3660. IOS is 124-9.T6. Both were very slow loading initial configuraitons. Is that because I set the RAM and NVRAM too low? (7206: 160M RAM and 96M RAM. 3660: 128M RAM and 64M NVRAM).

My PC is pretty new IBM with 2G RAM running XP SP3.


I have this problem too.
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Calin Chiorean Mon, 08/25/2008 - 04:44

Hello there!

I can tell you something from my experience with Dynamips maybe it helps.

I'm using Dynamips for simulation 6 router, 4 switches and 3 BB routers with complex config on a PC with AMD 64bit dual processor. Just to have an idea.

Now for your problem:

-if you have the possibility switch to a Linux OS; I don't have anything against Windows, but for me I could see the difference when switched to Linux

-unpack the IOS image and load the unpacked one, this will speed UP the booting of routers

-I'm using for the 3640 images 128 RAM and it is working OK (my machine has 3 GB RAM physical and about 1.7 are used with my lab above).

Also check your use of RAM and processor. If everything in moving very slow (I mean here also Win and other software) that you problem is related to resources not to Dynamips config.

Good luck!



patrickharrington Tue, 08/26/2008 - 06:54

I run GNS3 for all of my labs and can run between 6-8 routers while only using 35% CPU Utilization. The key is to increase your page file. Set it to 3x your physical memory. I am running a Intel Core 2 Duo 1.68 with 3 gig memory. My page file is 9 gig.....it will completely change your experience and allow you to perform other functions such as browsing without issues.


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