Starting from quarter 04/2022, the two NHR centers

• NHR@ZIB and
• NHR@Göttingen

follow the NHR-wide regulations and account in the new unit core hours.

Both NHR centers provide computational resources primarily to universities in Germany under public law.

• A user accesses an account containing a number of units core hour.
• The NHR centers charge for batch jobs on the compute systems. The charge for a job is a number of units core hour.
• Usage of persistent storage including tape library is currently not accounted.

Charge rates

The NHR centers operate different types of compute nodes (HLRN-IV system) organized in partitions, see Hardware. The charge rates for the partitions are given in the table.

*increased charge rate due to high memory layout

Job charge

The charge for a batch job on the NHR systems is the number of core hours and is calculated from the number of nodes reserved for the job, the wallclock time used by the job, and the charge rate for the job nodes. For a batch job with

• num nodes,

• running with a wallclock time of t hours, and

• on a partition with a charge rate charge_p

the job charge charge_j yields

charge_j = num * t * charge_p

Batch jobs running in the partition large96:shared access a subset of cores on a node. For a reservation of cores, the number of nodes is the appropriate node fraction.

Accounts for core hour

Running batch jobs with a user account, the user can access different accounts in general. The NHR centers distinguish between

• personal accounts and
• project accounts

User account

In the HLRN each user account is attached to a personal account. Both accounts, the user account and the personal account, share the same name but their purpose is different. The user account is the account on the Linux operation system and is used to control e.g. permissions to data files. The personal account is a bank account containing core hour.

At the beginning of each quarter the personal account is granted by 75000 core hour  during the lifetime of the user account. In reasonable and exceptional cases, the grant of the personal account can be extended to 300 k core hour per quarter. For that please contact your consultant. At the end of each quarter all remaining core hour in the personal account are dropped.

Project account

A compute project holds a project account. The project account is a bank account containing core hour for the project. At the beginning of each quarter the account is granted by the number of core hour following the funding decision for the compute project. Unused core hour are transferred to the subsequent quarter, but only one time.

In case of problems with core hour in the project account please look at /wiki/spaces/PUB/pages/425995 or contact your consultant. This might affect the

• application for additional core hour,
• movement of core hour between quarters.

Batch job and account

Batch jobs are submitted by a user account to the compute system. For each job the user chooses the account that will be charged by the job.

• For the user account the default account for compute time is defined on the link Informationen zu Ihrer Kennung/Account information of the service portal. At the beginning of the user account lifetime the default account is the personal account.

• The user controls the account for a job using the Slurm option --account at submit time.

To charge the account myaccount
add the following line to the job script. 
#SBATCH --account=myaccount

After job script submission the batch system checks the account for account coverage and authorizes the job for scheduling. Otherwise the job rejected.

You can check the account of a job that is out of core hour.
> squeue
... myaccount ... AccountOutOfNPL ...