Computing servers

On computing servers there is running Linux OS (Centos 6 or 7 distribution). You can connect with your standard faculty login credentials. Total number of currently available processor cores is 228 (1.1.2023), 1.75 TB of RAM and approx. 15 TB of total disk capacity.

Configuration of particular servers

• ELF - HP ProLiant DL560 G8, 4 processors Intel Xeon E5-4620 v2, 32 cores in total, 2.6 GHz, 256 GB RAM
• ELE - HP ProLiant DL580 G7, 4 processors Intel Xeon E7-4830, 32 cores in total, 2.13 GHz, 256 GB RAM
• ELD - HP ProLiant DL580 G7, 4 processors Intel Xeon X7560, 32 cores in total, 2.27 GHz, 256 GB RAM
• ELC - HP ProLiant DL560 G8, 4 processors Intel Xeon E5-4646, 32 cores in total, 2.4 GHz, 265 GB RAM
• ELB - HP ProLiant DL560 G8, 4 processors Intel Xeon E7-4880 v2, 60 cores in total, 2.5 GHz, 512 GB RAM
• ELA - HP ProLiant DL560 G9, 4 processors Intel Xeon E5-4627 v3, 40 cores in total, 2.6 GHz, 256 GB RAM

Home directories, scratch directories

All compute servers have shared home directories that are currently physically located on the ELC computer. Local path is

• /home/elc/

On other computers, home directories are shared over the network using NFS, which can slow down data access. In addition, a rather restrictive quota on the amount of data is applied to them, because users have the main home directories on the FSH storage - these are also accessible over NFS under the path

• /home/fsh/

or there is reference (link named FSH) from the home directory of each user.

So-called scratch directories are locally accessible on all computers, where users can temporarily store data and keep it there for as long as necessary. You can get the path to the scratch directories by combining the scratch name and the name (hostname) of the relevant computer, i.e.

• /scratch/ela
• /scratch/elc
• ...

These directories have access rights corresponding to temporary directories (/tmp) and thus everyone can create their own directory in which can store data. Create a directory whose name corresponds to your username, e.g., on the ELC computer it can be done with the following command

• mkdir /scratch/elc/

If you don't want other users to "see" into your directory (they can't delete your files), set their access rights with the following command

• chmod 700 /scratch/elc/

Warning: data in /scratch directories are not backed up! Really just think of them as temporary directories.  

Access to computing servers

In the computer classrooms, you can select the appropriate item from the computer startup menu (ELC, ELD, ...), from other computers you can connect using one of the following methods:

• terminal access over ssh - OpenSSH, PuTTy
• graphics interface over Xwindows - OpenNX, MobaXterm
• file transfer over ssh - SFTP, WinSCP

For OpenNX, it is necessary to use a certificate that can be found on any of the computing servers ELC, ELD, ... in the file /etc/nxserver/client.id_dsa.key. 

Load on computing servers