# mpi  !

Instances of Ubuntu Linux with [MPICH](https://www.mpich.org) -- portable implementation of Message Passing Interface (MPI) standard. Designed for MPI program development and deployment.

##  LabInstance mpi2


![alt text](images/swarmlab-network.png "")



> ### NOTE
>
>  Vlabs are reset every night around 02:00!
>
>> If you would like to keep your work please refer to "publish".
>
> Vlabs dont have firewall restrictions BUT the machines are not exposed to the internet.
>
> You share all machines so please be cooperative and discrete.
>




## Quickstart

This is a quickstart guide of howto use this *LabInstance to deploy MPI programs*

### HowTo use it


- cd /home/ubuntu

> git clone https://git.swarmlab.io:3000/labs/examples-mpi2.git

- cd examples-mpi2/examples

> make all


  

### Default Configuration 

- Working Directory

> /home/ubuntu

- Default user

> ubuntu


####  Find lab workers

The host file that contains addresses of connected workers can be created with:

>
> swarmlab-getworkers > /home/ubuntu/invhosts
>


#### connect to workers

```bash
 ssh ubuntu@[IP]
 Info:  user has sudo privileges without a password
```



- Compile

> mpicc -o /home/ubuntu/mpi_hello_world examples/mpi_hello_world.c

- run the MPI hello world program

> sudo -u mpi mpirun -n 10 -f /home/ubuntu/hosts  /home/ubuntu/mpi_hello_world


---
**NOTE:** copy hello world to all clients

```bash
# scp hello wrold to all clients. sudo -u mpi for auto scp connect. see /home/mpi/.ssh 
while read -r line; 
 do 
   sudo -u mpi scp /home/ubuntu/mpi_hello_world ubuntu@$line:/home/ubuntu/mpi_hello_world
done < /home/ubuntu/hosts
```
---
 

#### Publish Your Work


```bash

 mkdir /home/ubuntu/directory
 put your files and other directories into /home/ubuntu/directory
 swarmlab-publish /home/ubuntu/directory
 open URL in Browser

```


---
**MORE INFO** 

See swarmlab and examples directory
---