Difference between ITO and Genkai

Hardware

Between ITO and Genkai, the number and specification of computation nodes are significantly different. Please select the appropriate amount of resources according to the parallelism of the program to be executed and the amount of memory used.

The main differences between ITO and Genkai backend nodes are as follows

• ITO Subsystem A vs Genkai Node Group A

  Item	ITO A	Genkai A	Ratio
  Number of Nodes	2000	1024	0.51
  Cores per Node	36	120	3.3
  Speed per Node (SPEC CPU2017 FP Rate)	200	1040	5.2
  Memory per Node	192GB	512GB	2.7

• ITO Subsystem B vs Genkai Node Group B

  Item	ITO B	Genkai B	Ratio
  Number of NOdes	128	38	0.29
  GPU Speed per NOde (FP64)	21.2TF	134TF	6.3
  Memory per Node	384GB	1TB	2.7

Thus, the performance and memory per node of Genkai’s backend nodes are 2.7 to 6.3 times higher than ITO’s, but the overall number of nodes is much smaller. Therefore, using the same number of nodes as ITO may result in wasted computing resources and longer latency to start execution.

Application for use and changing contracts

When applying for use or making changes to your contract, ITO used to ask you to print out and mail in an application form, but with Genkai, you can basically apply and make changes on your Web browser. Please refer to the following page for application and modification procedures.

• Start Using Genkai

Usage fee

While ITO had a fixed monthly fee for all usage charges, Genkai uses a pay-as-you-go system for shared use of compute nodes. However, fixed usage and storage usage fees are charged on a fixed monthly basis in Genkai.

In addition, GenKai charges a basic monthly fee of 130 yen per group for each application for use. This basic fee includes the right to use 1TB of large-scale storage.

For more information about the usage fee, please refer to the following.

• Usage fee in Genkai

Login node

Specify the following as the IP address of the login node for Genkai.

genkai.hpc.kyushu-u.ac.jp

On a login node, memory usage per process is limited up to 16GB.

User and group

On Genkai, all user accounts are created anew. Therefore, user accounts currently used in ITO cannot be used on Genkai.

Genkai also limits the number of groups that a user account can belong to to one. In ITO, a single user account can belong to multiple groups when participating in multiple projects, and the user can switch groups by using the newgrp command. However, with this method, it was difficult to manage files for each project, as files for completed projects and ongoing projects were mixed in the same home directory.

Therefore, on Genkai, when one person participates in multiple projects, a separate user account is issued for each project. Accordingly, the setfacl command is used as a means to refer to the same files and directories in multiple projects. This allows you to freely set access rights to any file or directory you own for any other user account.

For more information on how to share files between users, refer to the following page.

Share files among users

Storage

In addition to the Large Storage where the home directory is located, Genkai offers Fast Storage consisting of SSDs. For more information on how to use the storage, see below.

Storage

Newly available software

Genkai has newly introduced the following software.

• Computational chemistry

  CP2K

• Machine learning

  MLflow

• Web interface

  Open OnDemand

• Workflow

  OPEN-WHEEL

• Cloud interface

  AWS CLI, AWS parallel cluster, Azure CLI, Azure CycleCloud, Google Cloud CLI, Oracle CLI

Software with usage restriction

Some of the software provided by ITO will be restricted in Genkai as follows.

• SAS

  This software is available in a bring-your-own-license format. If you wish to use it, please contact us as follows.

  Contact

• ANSYS

  This software’s license agreement makes it difficult to provide it on the National Joint-Use Computer, so we will stop providing it.

• MSC products

  The use of MSC products such as Marc/Mentat/Nastran/Patran is only available on Genkai computer nodes and login nodes. Using from MSC products installed on external PCs, etc., which was possible on ITO, is not possible on Genkai. Remote GUI startup is also not available.

module command

On ITO, the following command could display all available modules, regardless of dependencies between modules.

$ module avail

On the other hand, on Genkai, only modules that can be loaded at that time will be displayed. For example, a module that depends on a module intel will appear in the result of the module avail command after loading the intel module.

Programs compiled on ITO

To achieve maximam performance of Genkai, it is recommended that programs compiled with ITO be recompiled with the compilers on Genkai. Although Genkai is architecture compatible with ITO for both CPUs and GPUs, it may not be possible to run a program compiled on ITO without recompiling it, depending on the libraries used and other conditions.

Job scripts of ITO

Since Genkai uses the same Fujitsu Technical Computing Suite job scheduler as ITO, there are no major changes in the way job scripts are written on ITO.

However, at least the following items need to be modified.

• Specification of resource unit by -L rscunit, which was necessary on ITO, is not necessary on Genkai.
• The resource group specified by -L rscgrp is different between ITO and Genkai.
• When modules are loaded in a job script, module names are often different between ITO and Genkai.

Interactive use

On Genkai, interactive jobs can be reserved and used in place of ITO’s basic front-end nodes and large front-end nodes.

• Job Use

Interactive use via a Web browser is also possible by using Open OnDemand.

• Open OnDemand