Adding New Roll In Rocks-5.3

The Rocks way of installing the roll is as usual to reinstall your frontend and compute nodes, but you can also use the chain of commands to install a new roll on an existing frontend (with or without a previous version of the roll):

# rocks add roll /path/to/demo/roll.iso
# rocks enable roll demo
# rocks create distro
# rocks run roll demo | sh
# reboot

After the the frontend comes back up you should do the following to populate the node list:

# rocks sync config

then kickstart all your nodes

# tentakel /boot/kickstart/cluster-kickstart

After the nodes are reinstalled they should automatically pop up in the queueing system.

PREEMPTION IMPLEMENTATION USING MAUI

Following steps for configuring Maui for pre-emption:

SETTING OF PRE-EMPTION ENVIRONMENT

PREEMPTIONPOLICY :

The PREEMPTPOLICY policy has two possible options, namely –

RE-QUEUE - This terminates the job and re-queues the job
SUSPEND - This suspends the job and restarts it once the job that causes the pre-emption completes 

                                   PREEMPTPOLICY suspend/requeue

Pre Emptor’s and PREEMPTEE’s :

Queues can be either be a preemptor (i.e., a queue whose jobs can preempt others) or a preemptee (i.e., a queue whose jobs can be preempted) but not both.

You can define one queue as a preemptor and several as preemptee’s or several queues as preemptor’s and one as a preemptee.It can be done by using QOSCFG.

QOSCFG :

In order to configure premption activate the QOSWEIGHT, to do this set the variable QOSWEIGHT to a number greater than 1.

	QOSWEIGHT 10 

QOSCFG parameters to define which queues are preemptors and which are preempteed

			 QOSCFG[high]  QFLAGS=PREEMPTOR			 QOSCFG[low]   QFLAGS=PREEMPTEE			QOSCFG[default]   QFLAGS=PREEMPTEE

CLASSCFG :

Once you have defined which queues are preemptors and which are preemptees you can use the CLASSCFG to define priorities. As with the QOSCFG options you need to turn on the CLASSCFG options by setting the CLASSWEIGHT

CLASSWEIGHT 10 You then define CLASSCFG options for each QUEUE and define a priority and associate a QOSCFG with each CLASSCFG using the QDEF parameter CLASSCFG[high] QDEF=high PRIORITY=1100 CLASSCFG[low]  QDEF=low PRIORITY=1000 CLASSCFG[default]  QDEF=default PRIORITY=900

Checking Preemption Works :

There are two ways through which we can check the preemption :

1. Using command

showconfig | less 

check that the number PREEMPTOR and PREEMPTEES in the configuration is the same as the
number in the maui.cfg file.2.
The second check is to load the preemptee queue(s) and the submit jobs into the pre-emptor queue
and check that the jobs in the preemptee queue(s) are suspended and restarted once the jobs in
the preemptor queues complete. 

NOTE: With priorities the higher the number, the higher the priority

Building a Cluster Using Rocks

Installing Rocks for building Cluster made easy here …

How to mount a windows shared server on a linux machine

Mounting the shared window server on the linux machine :

Step 1 : Create a folder on which we would be mounting the windows server :

mkdir  name-of-the-folder

Step 2 : For Ubuntu user :

sudo mount -t cifs //ip-address-of-windows-server/name-of-the-shared-folder  path-of-the-folder-where-to-mount

–verbose -o user=server-username

For other user just login as root and run the following command:

mount -t cifs //ip-address-of-windows-server/name-of-the-shared-folder  path-of-the-folder-where-to-mount

–verbose -o user=server-username

Step 3 : After running this command if :

Using sudo it would be asking for the local machine password and then the windows server password

If executing the above command as a root then it would directly asking you to enter the windows server password

Install MPICH from Source

Pave your path through these easy steps for installing mpich2 :

Step 1. Download mpich2-1.1.tar.gz from here

Step 2. Make directory as :

mkdir /specify/the/directory/name

Step 3. Untar the content as :

tar -zxvf mpich2-1.1.tar.gz -C /give/folder/name/created/in/step2

(Note : Option “-C” untar the tar.gz file in the folder specified after that)

Step 4. Change the directory to :

cd /full/path/of/the/folder/in/step2

Step 5. Due some customization as per your system :

./configure –prefix=/path/of/the/newfolder/create/in/step2

–enable-nmpi-as-mpi –enable-mpe –enable-threads=multiple

–with-mpe CC=gcc F77=f77

(Note : Before doing this make sure the gcc , f77 and g++ compilers are installed on your system otherwise you would be getting a configuration error)

Step 6.Configuration would be taking some time after successful

configuration build the mpich2 library using :

make

(Note : If “make” is successful then move to step 7 else use “make clean” and try figure out the source of error)

Step 7. After doing “make” if you have not specified prefix in the           configuration step(step 5) then with root privileges do :

make install

else

if prefix is specified then do make install without root priveledges

This will install the parallel mpich2 library on your system.