Re: [help] Follow up for request: About Custom OS kernel running on GENI nodes.

[Sarah Edwards]

[forwarding your message to geni-...@googlegroups.com. For more information on how to sign up see [1] ]

Hi Jun Liu,

First, we just got your question about a custom OS kernel because your initial email was sent to geni.com (a geneology website) not geni.net. Please be sure to send messages to he...@geni.net or geni-...@googlegroups.com in the future.

Second, here are some recommendations. You should create a custom image using the modules you've described in your email and run it on a node which will give you the performance you need (either a bare metal node or perhaps a node with some performance guarantees).

Here are a couple of options:
1) If you would like to use ExoGENI, you can get VMs with one or more cores assigned solely to you. If having your own core gives you the performance you need, then this is a good option. To create the custom image from scratch [2] you can get an account on the ExoGENI playpen [3].
2) If you would like to use InstaGENI, you should request a bare metal node (InstaGENI oversubscribes VM resources so I suspect you won't get the performance you need with a VM or at least it may take some tweaking). To make your image, you can start with an existing image, modify it, and then run "createimage" to save a copy of that image [4].

We think primoGENI wouldn't be helpful for your situation because it is more about scaling than real-time.

If anyone on geni-users@ already has a real-time image that would be helpful to Jun Liu or relevant advice, please jump in.

Cheers,
Sarah Edwards, GPO

[1] GENI Users mailing list: https://groups.google.com/forum/#!forum/geni-users
[2] Custom image at ExoGENI: https://wiki.exogeni.net/doku.php?id=public:experimenters:images
[3] Using the ExoGENI playpen: https://wiki.exogeni.net/doku.php?id=public:experimenters:playpen
[4] Custom images on InstaGENI: http://groups.geni.net/geni/wiki/HowTo/ManageCustomImagesInstaGENI

On Mar 24, 2014, at 11:34 AM, Jun Liu <jl...@cs.und.edu> wrote:

> Hello,
>
> I would like to follow up the request with the ticket number #58097. I guess you have been busy working for the GEC. I still need to find a solution to my request.
>
> In our work, we need to use a linux OS kernel patched with the real-time module. I think there are others who also have the same request as we do. Here is the link for the real-time Linux RTwiki where the patches can be found.
>
> In particular, I would suggest that GENI can compile two Linux kernels patched with RT module as follows:
>
> a) 32-bit Linux OS kernel (i686) patched with rt20
> b) 64-bit Linux OS kernel (x86_64) patched with rt23 (Index of /pub/linux/kernel/projects/rt/3.12)
>
> There are quite many pre-patched RT Linux kernel sources, such as Linux @ CERN: /cern/mrg/slc5X/i386/RPMS/repoview/kernel-rt.html, etc.
>
> The RT-patched Linux kernel only makes the system call gettimeofday() to be handled promptly in order to reduce the extra delay from when gettimeofday() is called to when a timestamp is returned from this system call. A lot of network measurement programs are expected to run with real-time-like gettimeofday() to prevent Linux OS internal delays from messing up the actual network delays.
>
> We need both 32-bit and 64-bit real-time linux OS on which our programs can run. We are waiting for your response.
>
> Sincerely,
>
> Jun
>
> Begin forwarded message:
>
>> From: Geni Help Center <he...@geni.com>
>> Subject: Request received: About Custom OS kernel running on GENI nodes.
>> Date: March 10, 2014 at 2:02:31 PM CDT
>> To: Jun Liu <junli...@gmail.com>
>> Reply-To: Geni Help Center <he...@geni.com>
>>
>> ## Please do not write below this line ##
>> The world's largest family tree
>> Ticket #58097: About Custom OS kernel running on GENI nodes.
>> Your request (#58097) has been received, and is being reviewed by our support staff.
>>
>> To review the status of the request and add additional comments, follow the link below:
>> http://help.geni.com/requests/58097
>>
>>
>>
>> Jun Liu, Mar 10 08:30 AM:
>> Good Day,
>>
>> I have a question on booting up a custom kernel on GENI nodes. I want to
>> use a Real-Time-Clock enabled kernel to run our experiments. I wonder that
>> users have the ability of building our own kernel and uploadling the custom
>> kernel to a GENI repository. Then, the GENI nodes can be allowed to
>> download from the custom OS from the GENI repository.
>>
>> I also remember that there was a project called primoGENI which aimed to
>> allow users to run real-time experiments. However, I do not know how to get
>> primoGENI nodes. I am also unsure that our own real-time experiment utility
>> can run on primoGENI node without making additional modifications on our
>> utility.
>>
>> I am looking forward to hearing from you.
>>
>> Thanks.
>>
>> Jun
>>
>> This email is a service from Geni Help Center.
>> Message-Id:70364M3P_531e0c4769e97_44713fb0b32c9ea0991b_sprut
>

*******************************************************************************
Sarah Edwards
GENI Project Office

BBN Technologies
Cambridge, MA
phone: (617) 873-2329
email: sedw...@bbn.com