Gibbs

Revision as of 12:08, 19 November 2021

Description

Gibbs is equipped with the following software/hardware:

• 6 nodes with 2 x CPU Intel Xeon Octa Core (16 cores), 128 GB of RAM, 2 x 300 GB HD SAS (10 krpm), OS Red Hat Enterprise Linux Server release 6.3
• 4 nodes with 2 x CPU Intel Xeon 10 Core (20 cores), 128 GB of RAM, 2 x 300 GB HD SAS (10 krpm), OS Scientific Linux release 6.6
• 4 nodes with 1 x CPU Intel Xeon 24 Core, 256 GB of RAM, 2 x 300 GB HD SAS (10 krpm), OS Scientific Linux release 6.6

for a total of 14 nodes, 272 cores.

Access

• Linux and Mac OS users can login using a terminal. Windows 10 users can use the PowerShell.

The first step si to open a tunnel. Within the DiSC internet this can be simply done as:

ssh -L 2000:192.168.16.253:22 account@147.162.63.10 -p 7000

where "account" is the user's account.

Then, in a different shell, login as:

ssh -p 2000 account@localhost

Through port 2000 users can also transfer files directly via the tunnel using the scp command.

Troubleshootng

In some Linux distributions, the first attempt to open the ssh tunnel may fail with the following message:

Unable to negotiate with 147.162.63.10 port 7000: no matching key exchange method found. Their offer: diffie-hellman-group1.sh1

to solve such an issue, open (or create) the file

~/.ssh/config

and then add to the file the following lines

Host 147.162.63.10
      KexAlgorithms +diffie-hellman-group1-sha1

Please, counsult http://www.openssh.com/legacy.html for more information about this issue.

Queues

The queue manager is SLURM and the following queues are available:

• gibs: max nodes 4, max walltime 336:00:00 (2 weeks)

Example SLURM file

A typical SLURM script will be as follow (see the Support page for more help):

#SBATCH --job-name=name
#SBATCH --ntasks=1
#SBATCH --cpus-per-task=1
#SBATCH --partition=gibbs
#SBATCH --account=gibbs
#SBATCH --time=100:00:00

commands to execute

where the parts in italic should be changed as appropriate.