HPSS ( High Performance Storage System) is a system to organize the storage of big volumes of data. Read carefully the FAQ before any attempt to work with it.
H1 has space in the production machine, at the path:
- ccmdrs11:/hpss/in2p3.fr/group/hera1 = $H1HPSS
$H1HPSS is an environment variable. This
space is accessible only to registered users (at present: Cassol Brunner,
Diaconu,Matti,Sauvan,Schneider). Each user should write his personal
$H1HPSS/users/[user]and files of general interest in
$H1HPSS/...It is recommended to inform the webmaster each time new files are copied in the general part of hpss, to garantee a correct update of the web documentation.
The search of files in the HPSS tree is very slow. A parallel data-base has therefore been developed to keep trace of the files copied in HPSS. The H1 HPSS data-base is a mirror of $H1HPSS in $THRONG_DIR:
- $THRONG_DIR/h1hpss_db= $H1HPSS_DB
Each file in the data-base has the same path and name than in HPSS, but its content is substituted with statistic about the file. For example:
Device : 0
Inode number : 1
Protection : -rwxrwxr-x (100775)
Hard Links : 1
Uid : 2078 (cassol)
Gid : 116 (hera1)
Size (bytes) : 500041080
Last access : Wed Jul 11 09:38:18 2001
Last modify : Wed Jul 11 09:43:48 2001
Last stat. mod. : Wed Jul 11 09:43:48 2001
created to guarantee the correct
update of the data-base.
The H1 user access $H1HPSS
only through these commands!
h1rfcp [file1] [file2]:
"h1rfmkdir $H1HPSS/pippo"are equivalent).
HPSS file can be accessed by Root in an interactive section using the TFile::Open function and preceeding the file name by "rfio::". For example:
TFile* f=TFile::Open("rfio:ccmdrs11:/hpss/in2p3.fr/group/hera1/users/cassol/pippo.root")See also http://root.cern.ch/root/RFIOFile.html.
19/11/2002 F.Cassol Brunner