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Storage

Local user storage

• The local storage is a parallel GxFS Storage Appliance from NEC based on IBM Spectrum Scale: https://en.wikipedia.org/wiki/GPFS.
• All nodes are connected via a 100 Gb Mellanox/Inifiniband network.

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variable
30 €/TB/yr

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variable
10 €/TB/yr

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low latency, huge bandwidth

Remote user storage (/isibhv)

• You can access your online space on the Isilon in Bremerhaven (see https://spaces.awi.de/x/a13-Eg for more information) via the nfs-mountpoints
  /isibhv/projects
  /isibhv/projects-noreplica
  /isibhv/netscratch
  /isibhv/platforms
  /isibhv/home
• albedo is connected to the AWI backbone (including the Isilon and the HSM) via four eth-100 Gb interfaces.
  Each single albedo node has a 10 Gb interface.

Local (temporary) node storage on NVMe disks

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Note: /tmp will be deleted on a regular basis and /scratch will be deleted whenever necessary (filling state exceeds 95% or data >60 days old)

Compute nodes & Slurm

• To work interactively on a compute node use salloc. You can use all options (more CPU, RAM, time, partition, qos, ...) described below.

• You can ssh to a node where a job of yours is running, if (and only if) you have a valid ssh-key pair. (e.g. on a login node: ssh-keygen -t ed25519;  ssh-copy-id albedo1)

• To submit a job from the login nodes to the compute nodes you need slurm (job scheduler, batch queueing system and workload manager)

• A submitted job has/needs the following information/resources:
  

  What	Use	Default	Comment
  Name	-J or --job-name=
  Account	-A or --account=	primary section, e.g. clidyn.clidyn computing.computing	New on albedo (was not necessary on ollie) You can add a project (defined in eResources, you must be a member of the project) with -A <section>.<project>. This is helpful for reporting. e.g., clidyn.clidyn computing.tsunami clidyn.p_fesom
  Number of nodes	-N or --nodes=	1
  Number of (MPI-)tasks (per node)	-n or --ntasks= --ntasks-per-node=	1	Needed for MPI
  Number of cores/threads per task	-c or --cpus-per-task=	1	Needed for OpenMP If -n N and -c C is given, you get N x C cores.
  Memory/RAM per CPU	--mem=	ntasks x nthreads x 1.6 GB	Only needed for smp-jobs, mpp-jobs get whole nodes (cores and memory)
  Maximum walltime	-t or --time=	01:00
  Partition	-p or --partition=	smp
  qos (quality of service)	-q or --qos=	normal

  
  

• Please take a look at our examples scripts (from ollie) SLURM Example Scripts

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