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xrootd 를 활용한 SE Data 사용 가이드
voms proxy 생성
- xrootd 프로토콜을 이용하여 SE에 접근하기 위해서는 반드시 Grid 인증을 사용해야합니다.
$ voms-proxy-init --voms
xrdcp client 사용하기
$ xrdcp root://cluster142.knu.ac.kr//store/user/(username)/test.file /some/local/path/test.file (참조 : http://xrootd.org/doc/prod/Syntax_config.htm) $ xrdcp /some/local/path/test.file root://cluster142.knu.ac.kr//store/user/(username)/test.file
libXrdPosixPreload library 사용하기
$ export LD_PRELOAD=/usr/lib64/libXrdPosixPreload.so $ echo “This is a new test” >./test $ mkdir xroot://cluster142.knu.ac.kr:1094//store/user/(username)/testdir $ cp ./test xroot://cluster142.knu.ac.kr:1094//store/user/(username)/testdir/test $ cp xroot://cluster142.knu.ac.kr:1094//store/user/(username)/testdir/test ./test1 $ diff ./test1 ./test $ rm xroot://cluster142.knu.ac.kr:1094//store/user/(username)/testdir/test $ rmdir xroot://cluster142.knu.ac.kr:1094//store/user/(username)/testdir
XROOTD_VMP (xrootd virtual mount point) 사용하기 <- 추천
$ voms-proxy-init --voms # grid proxy 생성 $ export LD_PRELOAD=/usr/lib64/libXrdPosixPreload.so $ export XROOTD_VMP=cluster142.knu.ac.kr:/xrootd=/store # 가상의 마운트 포인트 /xroot에 root://cluster142.knu.knu.ar/store 로 설정 $ ls /xrootd/user/test # 가상의 mount point /xrootd $ ls /xrootd ReVal backfill data express generator group hidata himc hirelval lumi mc relval results temp test unmerged user $ ls /xrootd/user/test CE4D66EB-5AAE-E111-96D6-003048D37524.root test.transfer.20181004101241 test.transfer.20190503114034 test.transfer.20200818153523 OrthDatasetHistos_7.root test.transfer.20190116161947 test.transfer.20190503114035 test.transfer.20200818154436 test test.transfer.20190116174233 test.transfer.20190619153215 test.transfer.20200819171901 test.root test.transfer.20190117150051 test.transfer.20190619153842 test2 test.transfer test.transfer.20190128143636 test.transfer.20190919 testdir test.transfer.20180907142043 test.transfer.20190429141454 test.transfer.20191024200821 test.transfer.20180907142048 test.transfer.20190503114027 test.transfer.20191202153201
- 실재로 마운트된 상태가 아니기 때문에 다음과 같은 명령어는 동작하지 않습니다.
$ cd /xrootd/user/test -bash: cd: /xrootd/user/test: 그런 파일이나 디렉터리가 없습니다 $ echo "AAA" > /xrootd/user/test/aaa.txt -bash: /xrootd/user/test/aaa.txt: 그런 파일이나 디렉터리가 없습니다
xrdfs 사용하기
$ echo “This is a new test” >./test $ cat ./test “This is a new test” $ xrdcp ./test xroot://cluster142.knu.ac.kr:1094//store/user/(username)/test $ xrdfs cluster142 ls /store/user/(username) ... /store/user/(username)/test ... $ xrdfs cluster142.knu.ac.kr cat /store/user/(username)/test “This is a test” $ xrdfs cluster142.knu.ac.kr [cluster142.knu.ac.kr:1094] / > cd store/user/(username) [cluster142.knu.ac.kr:1094] /store/user/(username) > ls ... /store/user/(username)/test ... [cluster142.knu.ac.kr:1094] /store/user/(username) > ls test [ERROR] Server responded with an error: [3012] Error when processing list response: Not a directory: /pnfs/knu.ac.kr/data/cms/store/user/(username)/test [cluster142.knu.ac.kr:1094] /store/user/(username) > cat test “This is a test” [cluster142.knu.ac.kr:1094] /store/user/(username) > mkdir testdir [cluster142.knu.ac.kr:1094] /store/user/(username) > ls ... /store/user/(username)/test /store/user/(username)/testdir ... [cluster142.knu.ac.kr:1094] /store/user/(username) > mv test testdir [ERROR] Server responded with an error: [3005] Will not overwrite existing file (File exists:/pnfs/knu.ac.kr/data/cms/store/user/(username)/testdir). [cluster142.knu.ac.kr:1094] /store/user/(username) > mv test testdir/test [cluster142.knu.ac.kr:1094] /store/user/(username) > cd testdir [cluster142.knu.ac.kr:1094] /store/user/(username)/testdir > ls /store/user/(username)/testdir/test [cluster142.knu.ac.kr:1094] /store/user/(username)/testdir > rm test [cluster142.knu.ac.kr:1094] /store/user/(username)/testdir > cd .. [cluster142.knu.ac.kr:1094] /store/user/(username) > rmdir testdir [cluster142.knu.ac.kr:1094] / > quit Goodbye.
$ xrdfs --help
Usage:
xrdfs [--no-cwd] host[:port] - interactive mode
xrdfs host[:port] command args - batch mode
Available options:
--no-cwd no CWD is being preset
Available commands:
exit
Exits from the program.
tpc - support for third party copies
wan_port - the port to use for wan copies
wan_window - the wan_port window size
window - the tcp window size
cms - the status of the cmsd
role - the role in a cluster
sitename - the site name
version - the version of the server
checksumcancel <path> File checksum cancellation
checksum <path> File checksum
opaque <arg> Implementation dependent
opaquefile <arg> Implementation dependent
space <space> Logical space stats
stats <what> Server stats; <what> is a list
of letters indicating information
to be returned:
a - all statistics
p - protocol statistics
b - buffer usage statistics
s - scheduling statistics
d - device polling statistics
u - usage statistics
i - server identification
z - synchronized statistics
l - connection statistics
xattr <path> Extended attributes
rm <filename>
Remove a file.
rmdir <dirname>
Remove a directory.
truncate <filename> <length>
Truncate a file.
prepare [-c] [-f] [-s] [-w] [-p priority] filenames
Prepare one or more files for access.
-c co-locate staged files if possible
-f refresh file access time even if the location is known
-s stage the files to disk if they are not online
-w the files will be accessed for modification
-p priority of the request, 0 (lowest) - 3 (highest)
cat [-o local file] file
Print contents of a file to stdout.
-o print to the specified local file
tail [-c bytes] [-f] file
Output last part of files to stdout.
-c num_bytes out last num_bytes
-f output appended data as file grows
spaceinfo path
Get space statistics for given path.