User Environment

A. Account Issuance

1. Researchers who are authorized to use the Neuron system can apply for an account via the KSC website (https://www.ksc.re.kr) web service.

1) How to Apply : How to apply : Access the KSC website, (top) Application for use -> (top) Apply -> Select application

• Free account : Nurion system innovative support program, novice users

• Paid account : General and student users

• Once an account has been created, information related to the account will be sent to the email listed on the application

2) OTP (One-Time Password) authentication code issuance

• Based on the account information email you have received, send an email to [e-mail] by referring to the example below to receive an authentication code.

Subject	Request for an OTP authentication code - user ID (example) Request for an OTP authentication code - x123abc
Recipient	[e-mail]
Email body (example)	Login ID: x123abc Mobile phone number: 010-1234-5678 Name: Hong Gil-dong Network provider: LG U+ (or SKT/KT)

3) Install the OTP app

The OTP smartphone application is provided for secured access to the supercomputer.

For the OTP smartphone application, search for “Any OTP” on Google Play or App Store and install the application developed by Mirae-tech.

When logging into the supercomputer, the OTP security code of the “Any OTP” application must be entered.

※ If you do not use a smartphone, please contact the account manager ([e-mail]).

• Refer to the “OTP User Manual” by accessing the KISTI website > Technical Support > Guidelines for more details on OTP installation and use

• Emails will be sent out for users on the LG U+ network because text messages are processed as spam on this network

B. Login

Users can gain access through the login node (nurion.ksc.re.kr) of the Nurion system (refer to the node configuration below).

※ You can log in to MyKSC (KISTI Supercomputer Web Service Portal, https://my.ksc.re.kr) via a web browser to utilize GUI-based HPC and AI/data analysis services. (Refer to the MyKSC User Guide for instructions)

Default character set (encoding) is in unicode (UTF-8).

Only ssh, scp, sftp, and X11 are allowed to access the login node.

1. Unix or Linux environment

$ ssh -l <user ID> neuron01.ksc.re.kr -p 22

• [-p 22]: specifies the port number and can be omitted

• Use the XQuartx terminal to run the X environment.

※ Download the program from the Internet for free, and then install it.

2. Windows environment

Open Xming to run in the X environment.

※ Download the program from the Internet for free, and then install it.

Use ssh connection programs, such as putty, Mobaxterm, or SSH Secure Shell Client.

• Host Name: neuron.ksc.re.kr, Port: 22, Connection type: SSH

※ The programs can be downloaded from the Internet for free.

ssh -> X11 tap -> check “Enable X11 forwarding”

X display location: localhost:0.0

※ If you cannot connect owing to a DNS caching problem, clear the cache (run the ipconfig /flushdns command from the command prompt). Then, try to connect again.

C:￦> ipconfig /flushdns

3. Sending and receiving files

• Connect via ftp (can connect without OTP) or sftp using an FTP client, and send and receive files.

$ ftp neuron-dm.ksc.re.kr
or
$ sftp [user ID@]neuron-dm.ksc.re.kr [-P 22]

• Use a freely distributed FTP/SFTP client program, such as WinSCP, to connect in the Windows environment.

• When using FTP (File Transfer Protocol), Files can be sent without entering the OTP

• When using SFTP (Secure-FTP), the OTP must be entered to send files (a safer transmission method than FTP).

4. Node configuration

	Host Name	CPU Limit	Note
Login node	nneuron.ksc.re.kr (neuron01.ksc.re.kr, neuron02.ksc.re.kr, neuron03.ksc.re.kr)	120 minutes	• Can connect via ssh/scp • To compile and submit batch jobs • FTP/sftp not allowed
DM node	neuron-dm.ksc.re.kr	-	• SSH/SCP/SFTP/FTP access is available • Compiling and job submission are not supported

Detailed specifications of the login node

1) AMD node

• Host Name : neuron01.ksc.re.kr, neuron03.ksc.re.kr

• CPU : AMD EPYC 7543 2socket

• Memory : 512GB

• GPU: NVIDIA A100 (2 units, each configured with 7 instances for a total of 14 instances)

2) Intel Node

• Host Name : neuron02.ksc.re.kr

• CPU : Intel Xeon Gold 5217 2socket

• Memory : 384GB

• GPU : NVIDIA V100 1ea

※ The DM node mounts both the Nurion home directory (/nurion_home01/[userid]) and scratch directory (/nurion_scratch/[userid]), allowing file transfers between systems if the same user ID is used on both systems.

※ For downloading via wget or git, and for transferring large datasets, it is recommended to use the Datamover node, which has no CPU limits. (Performing these tasks on the login node may result in interruptions due to CPU limits)

5. Provision of debugging nodes

Two GPU nodes are provided for debugging, compiling, and testing execution codes (actual job execution is restricted).

Each node is equipped with 2 CPUs (Xeon 2.9GHz/32 Cores) and 2 GPUs (V100).

Direct SSH access is available from the login node (glogin[01,02]) by connecting to ssh gdebug01 or ssh gdebug02. Scheduler-based services are no longer supported.

C. Changing User Shell

• The default shell provided by the login node of the Neuron system is the bash shell. To change to a different shell, use the chsh command.

$ chsh

• Use the echo $SHELL command to check the current shell being used.

$ echo $SHELL

• The shell environment can be configured by modifying the environment configuration file (e.g., .bashrc and .cshrc) in the user's home directory

D. Changing User Password

Use the passwd command in the login node to change a user’s password.

$ passwd

※ Password-related security policy

The user password must be at least 9 characters and include an alphabet, number, and special character. English words in the dictionary cannot be used. The user password expiration period is two months (60 days).

• The new password cannot be the same as the five previously used passwords.

• Maximum number of incorrect login attempts : 5

  • The ID will get locked if you attempt to log in five times with the incorrect password; contact the account manager ([e-mail]) when your account is locked.

  • The IP address of a PC will be temporarily blocked if you attempt to log in five times with the incorrect password; contact the account manager ([e-mail]) in this case as well.

• Maximum number of incorrect OTP authentication attempts : 5

  • Contact the account manager ([e-mail]) if you have failed toauthenticate five times.

E. Time Allotted

Queue name (CPU type_GPU type_Number of GPUs)	Node name	Time allotted on the node per account	Hourly fee for using 1 node
cas_v100nv_8	gpu[01-05]	400	2,499KRW
cas_v100nv_4	gpu[06-09]	700	1,426KRW
cas_v100_4	gpu[10-24]	700	1,426KRW
cas_v100_2	gpu[25-29]	1,200	831KRW
amd_a100nv_8	gpu[30-35]	300	3,334KRW
skl	skl[01-10]	5,400	184KRW
bigmem	bigmem01	9,700	104KRW
	bigmem02	2,800	353KRW
	bigmem03	1,200	833KRW

※ Charges are applied based on the number of cores and GPUs used, in accordance with the shared node policy

※ For the latest pricing information, please refer to the Fee Calculator (https://www.ksc.re.kr/jwjg/gjbg/yggsg)

F. Work Directory and Quota Policy

• The following is information about the home directory and scratch directory.

* The Neuron system does not support backup.

The home directory has limited capacity and I/O performance; thus, all computation jobs must be executed in a user’s work space of /scratch, which is the scratch directory.

Check the capacity of the user directory (run from the login node)

$ neuroninfo (or quotainfo)

The file deletion policy(scratch purge policy) is applied based on the access time (atime) of the file attributes.

• atime(Access timestampe): the last time the file was accessed.

• mtime(Modified timestampe): the last time the file's content was modified.

• ctime (Change timestamp): the time when the inode of a file is changed due to modifications in permissions, ownership, or links.

※ In the existing purge policy (files that have not been accessed for 15 days are automatically deleted), recovery of deleted files is basically impossible, but some changes are made to the purge policy to provide a grace period for users who forget to manage files. (2023.05. applied)

After the purge policy is executed, the target file is prefixed with ToBeDelete_. e.g.) ToBeDelete_file1.txt, ToBeDelete_file2.txt

• If target file is needed, user must directly recover prefixed filename and update atime.

After a certain period of time (20 to 30 days), files marked with ToBeDelete_ will be deleted in bulk, and the files cannot be recovered.

atime can be checked with stat, ls -lu command, etc.

[login01 ~]# stat file1
File: ‘file1’
Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: 805h/2053d Inode: 3221237903 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2022-04-05 08:52:30.113048319 +0900
Modify: 2022-04-05 08:52:30.113048319 +0900
Change: 2022-04-05 08:52:30.113048319 +0900

$ ls -lu test.file
-rw-r--r-- 1 testuser testgroup 58 Jan 1 17:06  test.file

Last updated on November 08, 2024.