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Start and shut-down

log to grappolo via ethernet

  • Connect grappolo to ethernet network and turn on the power
  • from an external laptop or desktop connected to the same network as grappolo do ifconfig to find out the network IP address you are logged on. Next type
    sudo nmap -sP | grep -B2 00:00:00:00:08:49
    # or
    sudo nmap -sP | grep -B2 erox
    # replace 144.173.78 with the IP adrees of your network
    # use the resulting stdout IP address to log grappolo via ssh
    ssh # pass admin
    # or
    ssh  # pass stu1

log to grappolo via wifi

  • remove sd card from grappolo
    never remove SD card with power on!
  • Insert and read sd card from your laptop/desktop
  • edit the /etc/network/interfaces file as sudo user
sudo nano /etc/network/interfaces
  • Add network name and password to wpa-ssid and wpa-psk: <code bash> iface wlan0 inet dhcp wpa-conf /etc/wpasupplicant/wpasupplicant.conf wpa-ssid “NETWORKNAME” wpa-psk “NETWORKPASSWORD” </code>
to save and exit nano type ctrl + X and yes

Start the grid engine

  • once logged into grappolo, start the grid engine using the startup script:
# enter admin password : admin
# enter node1 password : node1pw
# enter node2 password : node2pw

Shut down grappolo

admin@grappolo:~$ ssh node1
admin@node1:~$ sudo poweroff # password: node1pw
admin@grappolo:~$ ssh node2 
admin@node2:~$ sudo poweroff # password: node2pw
admin@grappolo:~$ sudo poweroff # password grappolo: admin
leds from usb will be off, now you can power of grappolo

Submit jobs to GRAPPOLO

Computational implementation

Create a template script with all the commands you need to execute for your data processing routine. Save here: pi@grappolo ~/ost4sem/experiment/scripts/

In the example below we perform the following:

  • read the metadata of a raster image (.tif) and print these information on an output txt file
  • crop the raster image to the extent of a vector file (.shp format)
  • read the metadata of the newest cropped raster image (.tif) and printe these info on a new txt data.
#$ -S /bin/bash
# #$ -o /home/pi/ost4sem/experiment/stdout
# #$ -e /home/pi/ost4sem/experiment/stderr
CROPFILE=$(basename $file .tif)_fr.tif
gdalinfo $file > $OUTPUTDIR/$(basename $file .tif).txt
gdalwarp -cutline $INPUTDIR/poly_fr.shp -crop_to_cutline $file $OUTPUTDIR/$CROPFILE
gdalinfo $OUTPUTDIR/$CROPFILE > $OUTPUTDIR/$(basename $CROPFILE .tif).txt

The script below will perform the following:

  • List the images you need to process
  • Sent to process images individually using a dedicated CPU.

A job submission queuing list is created into a grid engine ( a software dealing with job submission queuing and priority). When the number of process in the queue is higher than the number of CPU available in the cluster, jobs to be processed are waiting.
The script is found in grappolo at: pi@grpi@grappolo ~/ost4sem/experiment/scripts/

for file in  ~/ost4sem/exercise/basic_adv_gdalogr/fagus_sylvatica/20*.tif ; do 
qsub -v file=$file $SCRIPTDIR/
wiki/grappolo_basic.txt · Last modified: 2021/01/20 20:36 (external edit)