Servers and Workstations
C&CZ manages ca. 900 Linux workstations and servers, and ca. 900 servers
and workstations with MS-Windows, primarily in the domain
science.ru.nl. Dual boot Windows/Linux machines are counted twice. The
ca. 350 servers are distributed over three datacenters, ca. 150 have a
fast network connection (25 Gb/s).
C&CZ manages (for departments) workstations with Ubuntu Linux or MS-Windows. There are also workstations in the PC-rooms for general use by anybody with a Science login, but also by all RU employees and students and guests with a temporary login. Almost all those machines are dual boot, the user can choose to boot Ubuntu Linux or MS-Windows.
Linux login servers
A few secure shell servers are available for Students and Staff of the Faculty (everyone with a Science account). You can use it just as you like, as long as you do not cause problems for other users.
The primary login server can be reached with the following address:
At the moment, lilo points to a machine called lilo7 (Ubuntu 20.04).
The ssh fingerprints for lilo7 and lilo8 are:
256 SHA256:si3g2elo5m6TShx3PjX0+vF50pZ8NK/iXz/ESB+ZeP0 lilo7 (ECDSA)
256 SHA256:wHypnsKnhOMcagDli8xSxp2AnRYXAIfs+EVNB1/LdiA lilo7 (ED25519)
3072 SHA256:Ce6uHmTO4693gFgFzSROlkSY2urZLpKm2i2Ibc9tQ6A lilo7 (RSA)
256 MD5:61:aa:8b:f7:d8:fb:a0:41:a9:ab:3b:33:89:7a:71:fd lilo7 (ECDSA)
256 MD5:47:0d:11:c8:65:4e:40:24:14:c0:6f:86:55:79:56:dc lilo7 (ED25519)
3072 MD5:2c:54:2a:7b:74:3b:8a:87:ba:80:b8:76:13:c2:eb:d4 lilo7 (RSA)
256 SHA256:yVihq2mnLULOCBFdvO2RWBps33hdE6PmaIGeBXX44wY lilo8 (ECDSA)
256 SHA256:gsvoEP5djMC5GsXJJUYktYq3TjRtNQPKo0/psULHBYc lilo8 (ED25519)
To avoid the following ssh warning everytime we replace hardware or change the alias for lilo or stitch
@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @
The ECDSA host key for lilo.science.ru.nl has changed
you can insert the following line into the file .ssh/known_hosts
@cert-authority *.science.ru.nl ecdsa-sha2-nistp521 AAAAE2VjZHNhLXNoYTItbmlzdHA1MjEAAAAIbmlzdHA1MjEAAACFBAHpJveyOrLKFRDsbiW/29OadbCbkmUaIXnWbhVwtytbpftAc7Stj2RYa8yBmgfdm82T/UBVu1tLbeeCYQI8UlCvbAALMx+I60ux+iEGVdDBgIOjeu6LuY12pksVlXy/nKc59+m3AdMXfGHA8cI/O8eFosQLJ+dck7SBcvTT4lPhEcSQxg==
In case you are behind a firewall that does not permit outgoing connections to the standard ssh port 22: our login servers also allow ssh connections to ports 80 and 443.
C&CZ manages a number of compute clusters, with compute nodes that
departments have purchased. In a few cases, departments have created a
separate cluster by also purchasing their own head node (master). The
cn-cluster also has a number of nodes purchased by C&CZ, so
FNWI departments may use these after approval by C&CZ. For departments
of FNWI the housing and management of clusternodes is free of charge.
cn-cluster is heterogeneous. All nodes have
SLURM as cluster software. As of February 2022, the
cn-cluster totalled 123 nodes with 4700 cores and 30 TB RAM. Several
clusternodes have a GPU with CUDA cores. The CPU-load of the
is being monitored.
The Astrophysics coma cluster with 1048 cores, 8780 GB RAM, 600 TB fileserver storage, GPU’s is a separate cluster. A separate cluster is also managed for the RU department Centre for Language Studies.
Sometimes outside of opening hours also the pcs in the computer labs are used as a compute cluster.
On the Do-It-Yourself website each user can
see which mail server will store incoming mail for his account. Mail can
be accessed with IMAP over SSL. The use of POP3 is supported, but not
advised. In every domain managed by C&CZ the alias
points to the machine that accepts mail with the SMTP-protocol. N.B.:
If one uses a (non-RU) Internet provider, our mail server will only
accept mail for our (RU) mail-addresses. Most other mail will not be
accepted (“Relaying Denied!”). One can prevent this by using the
smtp-server of the Internet-provider or by using Authenticated
The GitLab service provides a source code collaboration platform, git repository manager, issue tracker and code reviewer.
The ssh fingerprints for gitlab.science.ru.nl:
256 SHA256:BSSXi19WgCSpZu5AQkUTtwm+5zAMioQJpFE3oxBrIMQ root@gitlab (ECDSA)
256 SHA256:7G/4WD/tUE8H0k9MkBznlcx+ZWgUxnn3KazKm1XQwRk root@gitlab (ED25519)
2048 SHA256:NgZ9HciXlwG5JNPSFbem7bBbDbhqaNAO7JHag8rwi/I root@gitlab (RSA)
256 SHA256:pBFiBobAQTozB0xeeMCp3Du2PFtX7YIXw6XRFJSAGH0 root@gitlab (ECDSA)
256 SHA256:iWfwGvGZ/hdFImBzzG5Bu/y5gqhUkLOdSTYmzl1+k2w root@gitlab (ED25519)
2048 SHA256:lWWFUfhwODG0bBuQJUR8ymlVfqpNHrXk0xbFAoDpTIg root@gitlab (RSA)
One server is used to print jobs. See the printer webpage to see which server is advised in which situation.
These servers share different types of files, e.g. home-directories, application-software and disks for departments and groups. All modern servers only have redundant disks, sometimes by using “mirroring”, sometimes by use of a “RAID-array”. That means that loss of only 1 disk will not cause any problem for users.
To make it possible for users anywhere on the Internet to use servers and services as if one is connected to the campus network, a VPN service is available.
To make the transfer of large files to others simple, there is an FTP service. It can be accessed through the original FTP protocol as well as through the web HTTPS protocol. Anyone with a Science-account who acquired a directory on this server through postmaster, can copy files to that directory in several ways:
- by logging in to a login server like
- by attaching the network drive:
By using an unreadable upper directory containing a secret directory, one can even transfer somewhat sensitive data.
For several software packages there is a license server, that allows use of the software on all pc’s, while making sure that the total number of licenses uses is not more than what has been bought. Most of these license servers use FlexNet by Flexera.
Almost all disks that are managed by C&CZ, are being backupped regularly, in order to be able to restore data in case of small or large calamities.