We migrated workload managers of all clusters (including Barbora and Karolina) **from PBS to Slurm**!
We migrated workload managers of all clusters (including Barbora and Karolina) **from PBS to Slurm**!
For more information on how to submit jobs in Slurm, see the [Slurm Job Submission and Execution][7] section.
For more information on how to submit jobs in Slurm, see the [Job Submission and Execution][5] section.
# Resource Allocation
To run a [job][1], computational resources for this particular job must be allocated. This is done via the [Slurm][a] job workload manager software, which distributes workloads across the supercomputer.
## Job Submission and Execution
The `sbatch` or `salloc` command creates a request to the Slurm job manager for allocation of specified resources.
The resources will be allocated when available, subject to allocation policies and constraints.
**After the resources are allocated, the jobscript or interactive shell is executed on first of the allocated nodes.**
To run a [job][1], computational resources for this particular job must be allocated. This is done via the [Slurm][a] job workload manager software, which distributes workloads across the supercomputer. Extensive information about Slurm can be found in the [Slurm Documentation][b].
Read more on the [Job Submission and Execution][5] page.
## Resource Allocation Policy
## Resource Allocation Policy
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@@ -13,40 +21,21 @@ To run a [job][1], computational resources for this particular job must be alloc
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@@ -13,40 +21,21 @@ To run a [job][1], computational resources for this particular job must be alloc
Resources are allocated to the job in a fair-share fashion, subject to constraints set by the queue and resources available to the Project. [The Fair-share][3] ensures that individual users may consume approximately equal amount of resources per week. The resources are accessible via queues for queueing the jobs. The queues provide prioritized and exclusive access to the computational resources.
Resources are allocated to the job in a fair-share fashion, subject to constraints set by the queue and resources available to the Project. [The Fair-share][3] ensures that individual users may consume approximately equal amount of resources per week. The resources are accessible via queues for queueing the jobs. The queues provide prioritized and exclusive access to the computational resources.
### Resource Reservation
You can request a reservation of a specific number, range, or type of computational resources at [support@it4i.cz][c].
Note that unspent reserved node-hours count towards the total computational resources used.
!!! note
!!! note
See the queue status for [Karolina][d] or [Barbora][e].
See the queue status for [Karolina][d] or [Barbora][e].
Read more on the [Resource Allocation Policy][4] page.
Read more on the [Resource Allocation Policy][4] page.
## Job Submission and Execution
### Resource Reservation
The `qsub` command creates a request to the PBS Job manager for allocation of specified resources. The **smallest allocation unit is an entire node**, with the exception of the `qexp` queue. The resources will be allocated when available, subject to allocation policies and constraints. **After the resources are allocated, the jobscript or interactive shell is executed on first of the allocated nodes.**
Read more on the [Job Submission and Execution][5] page.
## Capacity Computing
!!! note
Use Job arrays when running huge number of jobs.
Use GNU Parallel and/or Job arrays when running (many) single core jobs.
In many cases, it is useful to submit a huge (100+) number of computational jobs into the PBS queue system. A huge number of (small) jobs is one of the most effective ways to execute parallel calculations, achieving best runtime, throughput and computer utilization. In this chapter, we discuss the recommended way to run huge numbers of jobs, including **ways to run huge numbers of single core jobs**.
Read more on the [Capacity Computing][6] page.
You can request a reservation of a specific number, range, or type of computational resources at [support@it4i.cz][c].
Note that unspent reserved node-hours count towards the total computational resources used.
