Initial configuration guide for first-time users
Here, it is about the initial setting after accessing. If you are using the Linux environment for the first time, we recommend you to follow the configurations below. It's not essential, and you can s
Install your grid CA
Issuing a certificate and signing up for VOCMS.
Certificates can be issued on the CERNCA website (https://ca.cern.ch/ca/) using the [New Grid User Certificate] item. Certificates are not authorized immediately after issuance. After issuance, you can visit VO CMS (https://lcgvoms24.cern.ch:8443/voms/cms/user/home.action) to get permission to use CMS resources.
Users can access CMS resources using a grid user certificate approved for VO CMS. Exceptionally, KISTI CMS Tier-3 users are enabled to access data stored in KISTI CMS Tier-3 without corresponding authentication. However, you must have a user certificate to access data from outside. In addition, in order for the user to submit grid jobs, it must be installed on the server where he or she wants to submit his or her certificate.
Certificate mapping
KISTI is also issuing certificates. (http://ca.gridcenter.or.kr/) In order to obtain the corresponding certificate and use it the same as the CERN certificate, you must perform a certificate mapping operation. In general cases, it is unnecessary because the certificate must be synchronized with the CERN computing account. However, KISTI certificates may be convenient if you work on projects other than CERN. (If other projects do not support certificate mapping)
CERN certificates are automatically mapped to CERN computing accounts, so you don't need to set them up separately, but if you get a certificate issued by KISTI, you must access the CERNCA website to do the mapping.
Certificates issued through CERN CA or KISTICA can be extracted into .pfx files through certificate management in the browser. You can upload this to the CMS Tier-3 UI server.
Certificate installation
For Linux or MacOS Users
Using scp command, the cert file can be copied to UI servers.
For Windows Users
To copy file, use MobaXterm's [Session] - [SFTP] option.
Converting cert and configuration
Below commands to convert from .pfxor .p12 to PEM format which is used for GRID application.
Setting CMSSW
CMSSW, CMS analysis framework, is distributed using CVMFS (CERN Virtual Machine File System) which is provided by CERN
You can CMSSW environment to follow the below commands.
After environment setting, you can use CMSSW command like scram, cmsenv . In addition, you can find available CMSSW version as below.
For analysis topic, CMSSW version may be different. In addition, Please note that the version of CMSSW that can be installed through the SCRAM_ARCH variable changes. For detail, please visit CMSSW GitHub homepage(http://cms-sw.github.io/showIB.html) or Release Map(https://cmssdt.cern.ch/SDT/releases.map)
(production version : type=Production;state=Announced;prodarch=1)
Create CMSSW directory
After checking CMSSW version, you can create a CMSSW work directory as belows.
Then, you should set up the environment according to CMSSW directory. It is necessary to use CRAB(GRID Job Tool).
Set up CRAB environment
CRAB is a GRID Job manager for CMS researchers.
You can set up the crab environment to use the CRAB command. You can use a crab environment source in CVMFS.
Before a GRID job submits, Please check your writing permission for T2_KR_KISTI and T3_KR_KISTI.
Please, follow the below commands to check the permission.
Checkwrite Result: Success: Able to write in /store/user/geonmo on site T2_KR_KISTI
If you fail this command, please contact us. (cmst3-support@kisti.re.kr)
Set up Rucio
Rucio is a dataset manager which was developed by ATLAS team. Recently CMS computing team choose Rucio as the next dataset manager instead of PhEDEx. For Rucio, you can set up the rucio environment as below.
Create /xrootd_users directory
The /xrootd space, long-term storage provided by KISTI CMS Tier-3, prohibits POSIX access from the OS. We recommend using 3rd party programs such as xrdfs and gfal-copy instead. However, to increase user convenience, we are mounting your storage space to UI servers in the /xrootd_users directory for applicants. (We don't mount it on WN.) When you want to your /xrootd_user directory, you must let us know the CERN account and KISTI account information. If you are not familiar with the CERN computing account, you can check it through the CRAB command below.
Retrieving DN from proxy... DN is: /C=KR/O=KISTI/O=KISTI/CN=58079576 Geonmo Ryu Retrieving username for this DN... username is geonmo
We will create your xrootd user directory if you request with CERN account ID.
You can use the xrootd_users directory as a POSIX mount. However, you should not use the mv command due to the limitation of our storage system.
The directory is set to autofs so that it can be automatically mounted upon user access. However, if you try to access it several times before mounting, the message below will be displayed due to mount collision and you will not be able to use it. If you see the message below, please contact us(cmst3-support@kisti.re.kr) immediately.
전송 종료지점이 연결되어 있지 않습니다 / Transport endpoint is not connected
Create SSH key pair for GitHub
Various analysis codes were uploaded on Github. If you just download that codes, you can use GitHub Token. However, we recommend registering your ssh public key.
To create SSH key pair, follow as below.
암호를 입력하지 않은 공개 및 비밀키를 만드시려면 Enter passphrase 항목에서 내용 없이 엔터를 입력하시면 됩니다. 해당 ssh 키 중 비밀키(id_rsa)는 절대 유출이 되면 안됩니다. 암호 없이 만들어지기 때문에 외부 유출이 되면 해킹의 위험이 크므로 관리를 철저히 해주시기 바랍니다. (패스워드 유무와 상관없이 비밀키는 유출되면 안됩니다.)
만약 암호를 설정하셨다면 ssh-agent를 이용하여 한번만 암호를 입력하시고 해당 세션 정보로 다른 서버로 접속하는 등의 기능을 사용하실 수 있습니다. 해당 내용은 여기서 다루지 않습니다.
생성된 공개키를 GitHub에 등록하시려면 해당 공개키의 정보를 확인하셔야 합니다. 간단하게 cat 명령어를 이용하여 내용을 확인하실 수 있습니다.
GitHub에 계정 가입 후 로그인을 한 후 [프로필 사진] - [계정 설정]을 클릭합니다.
[Settings] - [SSH and GPG keys] - [New SSH Key] 항목을 선택한 후 위에서 확인한 키 정보를 입력해줍니다.
등록이 완료되면 해당 저장소의 권한 설정에 따라 내용 수정 (commit)후 업로드(git push)가 가능해집니다. 물론, 저장소에 대한 권한이 없다면 불가능하오니 참고 바랍니다.
References
CERN CA (https://ca.cern.ch/ca/Help/?kbid=024010)
CMS TWiki page for lcg access (https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideLcgAccess)
CMS Workbook TWiki Page (https://twiki.cern.ch/twiki/bin/view/CMSPublic/WorkBook)
Last updated
