User guide: General servers.

Introduction

This document is intended as a guide for both new users in the system calculation of the Center for Scientific Computing at the Autonomous University of Madrid (CCC-UAM), as for regular users that eventually may have some doubts.

All servers in CCC-UAM have installed GNU/Linux as operating system , specifically the Rocky distribution, so the users must have some basic knowledge of the most usual commands.

In case of any doubt, the only way to access to the support in CCC-UAM is via email, specifically through the address:

administracion.ccc@uam.es

Computing system’s description.

The CCC-UAM hosts a heterogeneous group of servers from the points of view of processors, RAM, and hard drive storage. These servers are concentrated in two groups:

Servers belonging to CCC-UAM: available to all users and with an associated usage cost.

Servers belonging to a specific research group: housed in the premises of the CCC-UAM, available only to users of the research group concerned.

All computers are connected through a network that allows to transfer files between computers optimally.

CCC-UAM also maintains a centralized storage system supported by backup solutions.

Connecting to CCC-UAM.

The Center for Scientific Computing at the UAM has three servers to which you can establish a connection to use the same resources, these machines are:

• login1.ccc.uam.es
• login2.ccc.uam.es
• login3.ccc.uam.es

To establish a connection to them is necessary to use the ssh protocol. There are no differences from the Operating System from which you connect.

No access is allowed using unsecured connections.

In case you are using GNU/Linux as a client an example would be:

ssh login@login1.ccc.uam.es

where you can substitute login1.ccc.uam.es for any of the three servers mentioned before.

The first time you make a connection, the system will probably ask the confirmation of a certificate from the client in an equivalent message to:

The authenticity of host 'login1.ccc.uam.es (150.244.232.5)' can't be established.
RSA key fingerprint is 7a:fb:38:f3:6d:e4:d7:1b:08:a6:7b:83:a6:94:b2:07.
Are you sure you want to continue connecting (yes/no)?
  

To continue you must type yes. If you are using a graphical program to perform ssh connections, please follow the instructions in the program to accept this certificate.

Connections will be allowed as long as they are made from an IP address within the Autonomous University of Madrid's range, that is, connections will be allowed from devices physically located at the Autonomous University of Madrid using WiFi or using the VPN of the Autonomous University of Madrid.

Password management.

To change the password, you have to make a connection to any of the three servers and then run:

passwd

The system will ask you for the old password and then allow the entry of the new one, asking you to repeat this again for safety reasons.

Passwords must be at least ten characters and necessarily must consist of at least one lowercase letter, one uppercase letter, one number and one special character.

If when trying to change the password the system warns that any of these rules was not followed or understands that the chosen password is weak it will require the user to choose a different one.

It is not recommended to keep the password written on paper in an open environment. Spoofing can cause serious troubles.

The password expires after six months. You have seven days in order to change the password in this case. After this time you accout will be blocked, and it could be unlock only writing an email to the support addresss.

After a month, blocked accounts will be removed from the system. The data of this accounts will be removed, and it could not be recover.

Storage.

The CCC-UAM has four centralized file systems, that is, they can be accessed equally from any server. These are:

• /home
• /home/proyectos
• /usr/local
• /scratch

The first one, /home, is the filesystem where the home directories are located. For example, the user's home directory of login is /home/login.

/home/proyectos is a file system which contains the data of various compute-intensive projects. Each project manager may request the creation of some project space, by specifying the maximum capacity that it should have through the project request form available on the website of the CCC-UAM or by sending an email to the centralized email address.

/usr/local filesystem is where the different software programas are available to all users.

Finally, /scratch filesystem contains a subdirectory for each users, the same as in /home, but it should be use to save temporary data from jobs executed through the queue system. /scratch has no backup, so the data saved in this filesystem could be deleted after a period of non-use of the files.

Besides, each server has available a local filesystem named /temporal. In this system there is a directory for each user login, where he/she can write data needed for successfully carrying out the calculations that are running on that machine. For example, the directory of login bould be locally /temporal/login. Since this is a local file system, it is imperative that users modify their running applications scripts in order to store in it the intermediate files for the calculations and not in centralized storage systems. The performance improvement in this case is substantial.

File systems /home, /home/projects and /usr/local are supported through backups, but in no event the system will backup the information stored in /scratch nor /temporal filesystems.

/home/login, /scratch/login and /temporal/login directories are the responsibility of the person who owns the login. Project directories in /home/projects are the responsibility of the person responsible for the project.

File transfer.

To transfer files to the CCC-UAM you should use scp or sftp by using the command directly if you use a GNU / Linux or equivalent, or other operating systems through graphics applications that support these mechanisms.

The username and password you use to make such transfers is the same as used to make the connections. You can also use any of the three servers access to carry out the transfer.

For example from a GNU/Linux environment the scp command performs a directory transfer, including all its contents from your PC to CCC-UAM. You must execute in your computer:

scp -r directory-to-transfer login2.ccc.uam.es:/home/login

This will transfer the whole content of the directory to your home directory:

where XXX is your login account.

Job execution.

The resource manager used in the CCC-UAM is Slurm, so we recommend you to visit the Slurm users guide..

Misuse.

The misuse of the resources of the CCC-UAM will lock the user account until the cause and extent of such is determined and can lead to permanently lock the user account.

If account misuse constitutes criminal activity, it will be reported to the relevant authorities.

Updated on November 4, 2025.

Users guide: Cibeles node. RES.

Introduction.

This document is intended as a guide for both new users in the Cibeles node from the Spanish Supercomputing Network..

All Cibeles servers have installed GNU/Linux, as operating system, specifically the Rockydistribution, so the users must have some basic knowledge of the most usual commands.

In case of any doubt, the only way to access to the support in CCC-UAM is via email, specifically through the address: res_support@uam.es.

Servers description.

Cibeles node has two different clusters, Cibeles3 y Cibeles4, both using the main Lustre filesystem we have in the Center for Scientific Computing in the Autonomous University of Madrid.

• Cibeles3: is a cluster with 28 servers, each one with 2 Intel Xeon Gold 6330 2.0Ghz processors and 512GB of RAM memory. This cluster has 1568 cores and a maximun performance of 100 TFlop/s. The interconnection network in this cluster is Infiniband HDR with 200Gbps without oversuscription.
• Cibeles4: is a cluster originating from Barcelona Supercomputing Center - Centro Nacional de Supercomputación, being MareNostrum4 in origin. This cluster has 72 servers accessibles from RES accounts. Each one has two Intel Xeon Platinum 8160 2.10Ghz processors and 96GB of RAM memory. This cluster has 3456 cores and a maximum performance of TFlop/s. The inrconnection network is Intel OmniPath with 100Gbps.

Connecting to the Cibeles Node.

The Center for Scientific Computing at the UAM has three servers to which you can establish a connection to use the same resources, these machines are:

• login1.ccc.uam.es
• login2.ccc.uam.es
• login3.ccc.uam.es

To establish a connection to them is necessary to use the ssh protocol. There are no differences from the Operating System from which you connect.

No access is allowed using unsecured connections.

In case you are using GNU/Linux as a client an example would be:

ssh login@login1.ccc.uam.es

where you can substitute login1.ccc.uam.es for any of the three servers mentioned before.

The first time you make a connection, the system will probably ask the confirmation of a certificate from the client in an equivalent message to:

The authenticity of host 'login1.ccc.uam.es (150.244.232.5)' can't be established.
RSA key fingerprint is 7a:fb:38:f3:6d:e4:d7:1b:08:a6:7b:83:a6:94:b2:07.
Are you sure you want to continue connecting (yes/no)?
  

To continue you must type yes. If you are using a graphical program to perform ssh connections, please follow the instructions in the program to accept this certificate.

Connections will be allowed as long as they are made from an IP address within the Autonomous University of Madrid's range, that is, connections will be allowed from devices physically located at the Autonomous University of Madrid using WiFi or using the VPN of the Autonomous University of Madrid.

In the event that one or more of theses circumstances cannot be met by one or more people in the project authorized to calculate in the Cibeles node, an access request can be made, sending an email message to the previously indicated support address stating the need for the connection, the RES project, the logins that will use the connection and the static IP address to be used.

Password management.

To change the password, you have to make a connection to any of the three servers and then run:

passwd

The system will ask you for the old password and then allow the entry of the new one, asking you to repeat this again for safety reasons.

Passwords must be at least ten characters and necessarily must consist of at least one lowercase letter, one uppercase letter, one number and one special character.

If when trying to change the password the system warns that any of these rules was not followed or understands that the chosen password is weak it will require the user to choose a different one.

It is not recommended to keep the password written on paper in an open environment. Spoofing can cause serious troubles.

The password expires after six months. You have seven days in order to change the password in this case. After this time you accout will be blocked, and it could be unlock only writing an email to the support addresss.

After a month, blocked accounts will be removed from the system. The data of this accounts will be removed, and it could not be recover.

Almacenamiento

The cibeles Node has four centralized file systems, that is, they can be accessed equally from any server. These are:

• /home
• /home/proyectos
• /usr/local
• /scratch

The first one, /home, is the filesystem where the home directories are located. For example, the user's home directory of login is /home/login.

/home/proyectos is a file system which contains the data of various compute-intensive projects. Each project manager may request the creation of some project space, by specifying the maximum capacity that it should have through the project request form available on the website of the CCC-UAM or by sending an email to the centralized email address.

/usr/local filesystem is where the different software programas are available to all users.

Finally, /scratch filesystem contains a subdirectory for each users, the same as in /home, but it should be use to save temporary data from jobs executed through the queue system.

Each project would have a directory in this filesystem. The name of this directory will be the same as the RES project name. In this directory people from the RES project, authorized by the person responsible for the project as long as they are part of it, could save data.

/scratch has no backup, so the data saved in this filesystem could be deleted after a period of non-use of the files.

Besides, each server has available a local filesystem named /temporal. In this system there is a directory for each user login, where he/she can write data needed for successfully carrying out the calculations that are running on that machine. For example, the directory of login bould be locally /temporal/login. Since this is a local file system, it is imperative that users modify their running applications scripts in order to store in it the intermediate files for the calculations and not in centralized storage systems. The performance improvement in this case is substantial.

File systems /home, /home/projects and /usr/local are supported through backups, but in no event the system will backup the information stored in /scratch nor /temporal filesystems.

/home/login, /scratch/login and /temporal/login directories are the responsibility of the person who owns the login. Project directories in /home/projects are the responsibility of the person responsible for the project.

File transfer.

To transfer files to the CCC-UAM you should use scp or sftp by using the command directly if you use a GNU / Linux or equivalent, or other operating systems through graphics applications that support these mechanisms.

The username and password you use to make such transfers is the same as used to make the connections. You can also use any of the three servers access to carry out the transfer.

For example from a GNU/Linux environment the scp command performs a directory transfer, including all its contents from your PC to CCC-UAM. You must execute in your computer:

scp -r directory-to-transfer login2.ccc.uam.es:/home/login

This will transfer the whole content of the directory to your home directory:

where XXX is your login account.

Job execution.

The resource manager used in the CCC-UAM is Slurm, so we recommend you to visit the Slurm users guide..

When executing distributed memory jobs, MPI as an example, please do not mix Cibeles3 with Cibeles4 machines, because they use different high speed networks.

To work easily with these machines, it has been configurated in Slurm a feature called cibeles3 in the Cibeles3 machines and cibeles4 in the Cibeles4 machines.

With these features you can force to use only Cibeles3 machines using --constraint=cibeles3 in you sbatch command, and you can use --constraint=cibeles4 in the case you want to use only Cibeles4 machines.

The software adapted to work on Cibeles4 machines must be loaded thanks to a module load command using the extension "-OPA".

Misuse.

The misuse of the resources of the CCC-UAM will lock the user account until the cause and extent of such is determined and can lead to permanently lock the user account.

If account misuse constitutes criminal activity, it will be reported to the relevant authorities.

Updated on November 4, 2025.