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Log in

Users connect to MetaCentrum by using ssh to any of the login nodes called frontends.

Grid overall scheme

In Linux, macOS, Windows PowerShell and MobaXterm the ssh command can be given in the terminal.

Open the terminal and on CLI type

ssh your_username@frontend
  1. Open PuTTY
  2. Specify frontend name as Host name
  3. Use default port 22
  4. Use SSH connection type, protocol version 2
  5. Click on "Open"
  6. A terminal should appear prompting for your MetaCentrum username and password.
  7. On the command line type
ssh your_username@frontend

If you log in for the first time, you will be prompted by a query similar to the following:

The authenticity of host 'skirit.ics.muni.cz (2001:718:ff01:1:216:3eff:fe20:382)' can't be
established. ECDSA key fingerprint is SHA256:Splg9bGTNCeVSLE0E4tB30pcLS80sWuv0ezHrH1p0xE.
Are you sure you want to continue connecting (yes/no)?

Type "yes". The public key of the frontend will be saved to your ~/.ssh/known_hosts file.

Tip

Strictly speaking the user should always verify a new key before adding it to a list of known hosts. For a howto on SSH key verification, see more detailed page on SSH key verification.

Once the terminal connection to a frontend is open you can start using it with the Linux command line tools (bash shell).

A complete list of frontends is given below. You can use any of them. We encourage users to pick one that is closest to their physical location (city) to minimize network lag.

Tip

In case your favourite frontend is down or going just too slow, do not hesitate to use another one.

Frontend address Aliased as Native home OS Physically located in Note
zenith.cerit-sc.cz zenith.metacentrum.cz /storage/brno12-cerit Debian 12 Brno
nympha.meta.zcu.cz nympha.metacentrum.cz,
nympha.zcu.cz,
minos.zcu.cz,
minos.meta.zcu.cz
/storage/plzen1 Debian 12 Plzen
skirit.ics.muni.cz skirit.metacentrum.cz /storage/brno2 Debian 11 Brno
alfrid.meta.zcu.cz alfrid.metacentrum.cz /storage/plzen1 Debian 11 Plzen
tarkil.grid.cesnet.cz tarkil.metacentrum.cz /storage/praha1 Debian 12 Praha
perian.grid.cesnet.cz perian.metacentrum.cz,
onyx.metacentrum.cz
/storage/brno2 Debian 12 Brno
charon.nti.tul.cz charon.metacentrum.cz /storage/liberec3-tul Debian 11 Liberec
tilia.ibot.cas.cz tilia.metacentrum.cz /storage/pruhonice1-ibot Debian 12 Pruhonice
zuphux.cerit-sc.cz zuphux.metacentrum.cz /storage/brno12-cerit CentOS 7.9 Brno
elmo.elixir-czech.cz elmo.metacentrum.cz /storage/praha5-elixir Debian 11 Praha
oven.ics.muni.cz oven.metacentrum.cz /storage/brno2 Debian 11 Brno Reserved to access oven node only
luna.fzu.cz luna.metacentrum.cz /storage/praha1 Debian 11 Praha Reserved for FZU users

Warning

The frontend nodes can be used for light pre- and postprocessing and manipulation of data. All other tasks must be submitted as jobs to the batch job system. If you need to run something interactively, submit an interactive job.

Kerberos

After the user enters MetaCentrum infrastructure by logging in, they will need also to be able to move between computational nodes, reach storage spaces residing on different machines etc. It would be very inconvenient to authenticate by password every time. Therefore the authentication of user within the MetaCentrum infrastructure is done by Kerberos protocol.

Grid security protocols scheme

After the user logs in, they automatically obtain a Kerberos tickets. As long as the ticket is valid, user can move between machines, run jobs, copy files without bothering about the authentication.

Warning

The ticket is valid for 10 hours. If you stay logged in for longer, you will need to re-generate your ticket with kinit command.

Basic Kerberos commands

  • klist - list all current tickets
  • kdestroy - delete all tickets
  • kinit - create new Kerberos ticket

It is also possible to install Kerberos on your PC. For more in-depth info, see Kerberos advanced page.