...
This rule applies to each cluster based on its amount of total memory and cores.
"Non-exclusive" nodes: TMPDIR matters (LEONARDO only)!
On LEONARDO, the job's TMPDIR local area is managed by the slurm job_container/tmpfs plugin and can be explicitly requested on the diskful nodes. In this case, the accounting procedure also takes into account the amount of space (gres/tmpfs) you request for your job. If you ask for an amount of local storage that is larger than the equivalent number of cores requested, the jobs will be billed for a larger number of cores than the ones you have reserved.
The billing always follows the basic idea illustrated above, but a generalized parameter for the number of reserved cores, accounting for the local storage request, is now used:
accounted hours = ElapsedTime x ReservedCoresEquiv
where
ReservedCoresEquiv = ReservedCores x LocalStorageFactor
- LocalStorageFactor = 1
If the local storage you ask for (in terms of the equivalent number of cores) is smaller than or equal to the number of reserved cores. In this case, the amount of cpu-hours billed depends only on the number of requested cores.
LocalStorageFactor = (ReservedLocalStorage / TotalLocalStorage) / (ReservedCores / TotalCores)
If the local storage you ask for (in terms of the equivalent number of cores) is larger than the number of reserved cores. In this case, the amount of cpu-hours billed also depend on the amount of local storage requested (i.e. the actual percentage of node allocated).
For example, on LEONARDO-DCGP partition, the TotalLocalStorage considered to calculate the LocalStorageFactor is 3 TB, and each compute node has 112 cores:
- TotalLocalStorage = 3 TB
- TotalCore = 112
If you ask for only one core and 1 TB of memory (thus allocating for yourself one third of the local storage of the node even if you are using one core), the LocalStorageFactor is:
- ReservedLocalStorage = 1 TB
- ReservedCores = 1
- → LocalStorageFactor = (1 TB / 3 TB) / (1 / 112) = 37
Hence, with such a request for each hour of computation, your budget will be billed for 37 equivalent CPUs, i.e., for 37 hours.
At present the slurm job_container/tmpfs plugin is ONLY enabled on LEONARDO.
Accounting and accelerators
...