Using the Weizmann Cluster Nov

Overview Weizmann Cluster Connection Basics Getting a Desktop View Working on cluster machines GPU For many more details, please visit:

Cluster Structure The Weizmann cluster Two types of machines: – Workstations: Math-lx : for lightweight interactive sessions (math01-lx, math02-lx,…, math13-lx) – Cluster Machines: MCluster01, MCluster03 : clusters of strong machines designed for the “heavy lifting” (multiple cores, lots of RAM) – In MCluster01 we have some GPU machines (more on this later)

General Flow 1.Connect to a workstation 2.get a GUI using VNC 3.Connect to a cluster machine via the workstation 4.Do some work

Connecting to a Workstation: Putty SSH : a protocol enabling a secure connection to another host Putty is a windows SSH client. To connect* to one of the math-lx machines: – Launch Putty – In the session->Host name field, enter e.g: math05-lx In the terminal window, enter user/password as required *Assuming you’re inside the Lab

Getting a Desktop GUI: > VNCserver VNC allows remote connection to a desktop Install VNC on your windows machine. Available clients: UltraVNC, TightVNC On remote machine, start a VNC server, as follows: > vncserver_: _-geometry_ x Example > vncserver :500 -geometry x Without the a port will be chosen arbitrarily and VNC will output the chosen number These are spaces!

VNC continued The number allows concurrent vnc servers (e.g for different users). Once the VNC server is running, run UltraVNC on your PC. enter in the “vnc server” field : :N where N=5900+DisplayNumber Connect Congratulations! You just started an Interactive session

Ending a session: > vncserver -kill Closing a VNC viewer will not end you session! Instead, enter >vncserver –kill :N Where N is the chosen display port.

Working on the Cluster The machines on the cluster are split into different queues, according to the memory, number of cores, etc. of the machines Usually you do not connect explicitly to a specific machine, but request a machine from one of the queues, depending on your needs To see the queue load and available queues, go to : To see load of all machines on a clusterload of all machines on a cluster

Connecting to a Cluster Machine To request a cluster machine, use: >ssh -X mcluster01 qsh -q amd64g.q -display HOST$DISPLAY This does the following: – Submits an interactive session request to be fullfilled by a machine from the specified queue, in this case amd64g.q – Forwards the graphics to your host and display For a GPU machine the queue is gpu.q >ssh -X mcluster01 qsh -q gpu.q -display HOST$DISPLAY If you need a specific node, add -l hostname=n82

GPU machines Currently 6 GPU machines: – node x 12GB GPU – node x 12GB GPU – node x 12GB GPU – node x 12GB GPU – node x 6GB GPU – node x 12GB GPU + 1 x 6GB GPU 512GB RAM 256GB RAM

Monitoring GPU memory GPU memory is a shared In principle, as long as there’s free memory, it supports more concurrent users nvidia-smi To see continuously: use watch >watch –n.5 nvidia-smi (this will update the status every 0.5 seconds)

Summary Putty + VNC  connect to math_-lx Ssh+qsh : connect to cluster machine Ssh+qsh+gpu.q : connect to GPU machine No need to memorize! Helpful scripts on course website – es/2016_1/DNN/utils.html es/2016_1/DNN/utils.html is your friend!