Connecting to a HPC resource
If using SSH keys, once the keys are created and uploaded on the PDC interface, entering the cluster is as simple as:
$ ssh -Y <username>@dardel.pdc.kth.se
Which should get you into the PDC supercomputer. The -Y
flag is used to be able to open graphical windows on the supercomputer, e.g.
to visualise images. This will work only if you have a running local X server (if you are on Linux/WSL, you most likely do).
Alternatively, you may choose to use Kerberos as an authentication method. To do that, you first need to ask for a Kerberos ticket:
$ kinit -f <username>@NADA.PDC.KTH.SE
After that, the SSH command looks like the following:
$ ssh -o GSSAPIAuthentication=yes -Y <username>@dardel.pdc.kth.se
More information about Kerberos can be found at this address.
Type-Along
Let us check on which node we ended up. The name of the machine can be checked with the hostname
command:
$ hostname
We can get a sense of the size of Dardel by using the sinfo
command:
$ sinfo -s
PARTITION AVAIL TIMELIMIT NODES(A/I/O/T) NODELIST
gpu up 1-00:00:00 49/9/4/62 nid[002792-002853]
main up 1-00:00:00 604/256/112/972 nid[001012-001531,001756-001816,001818-001819,001821-001896,001898-002007,002009-002023,002552-002567,002588-002759]
scania up 4-00:00:00 22/187/15/224 nid[001532-001755]
scania-hf up 4-00:00:00 0/3/1/4 nid[000011-000014]
memory up 7-00:00:00 34/8/0/42 nid[000101-000118,001772-001779,002552-002567]
shared up 7-00:00:00 27/5/0/32 nid[001000-001011,002568-002587]
long up 7-00:00:00 76/4/0/80 nid[001800-001819,002588-002647]
eggnog up 7-00:00:00 4/0/0/4 nid[002536-002539]
supernova up 14-00:00:0 5/6/5/16 nid[001817,001820,001897,002008,002540-002551]
E.g. the main
partition has 972 nodes, each containing 128 cores.
A general sense of the amount of work load can be gained with the squeue
command, which shows all the jobs (running, queued):
$ squeue