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$HOME: permanent/backed up, user specific, local
This is a local area where you are placed after the login procedure. It is where system and user applications store their dot-files and dot-directories (.nwchemrc, .ssh, ...) and where users keep initialization files specific for the systems (.cshrc, .profile, ...). There is a $HOME area for each username on the machine.
This area is conceived to store programs and small personal data. It has a quota of 50 GB. Files are never deleted from this area, moreover they are guaranteed by daily backups: if you delete or accidentally overwrite a file, you can ask our Help Desk (superc@cineca.it) to restore it. A maximum of 3 versions of each file are stored as a backup. The last version of the deleted file is kept for two months, then definitely removed from the backup archive. File retention is related to the life of the username, data are preserved until the username remains active.
$WORK: permanent, project specific, local
This is a scratch area for collaborative work within a given project. File retention is related to the life of the project. Files in $WORK will be conserved up to 6 months after the project end, then they will be cancelled. Please note that there is no back-up on this area.
This area is conceived for hosting large working data files, since it is characterized by high bandwidth of a parallel file system. It behaves very well when I/O is performed accessing large blocks of data, while it is not well suited for frequent and small I/O operations. This is the main area for maintaining scratch files resulting from batch processing.
There is one $WORK area for each active project on the machine. Default quota is 1 TB per project, but extensions can be considered by Help Desk (mailto: superc@cineca.it) if motivated. Owner of the main directory is the PI (Principal Investigator) of the project, all collaborators are allowed to read/write in there. Collaborators are advised to create a personal directory in $WORK for storing their personal files. By default the personal directory will be protected (only the owner can read/write), but protection can be easily modified, for example by allowing write permission to project collaborators through chmod command. This second approach does not affect global files security.
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$CINECA_SCRATCH: temporary , user specific, local
This is a local temporary storage, like $WORK, conceived for temporary files from batch applications. There are important differences with respect to $WORK area. It is user specific (not project specific) and it can be used for sharing data with people outside your project. By default, file access is open to everyone, in case you need more restrictive protections, you can set them with chmod command.
On this area, a periodic cleaning procedure could be applied, with a normal retention retention time of 40 days: files are daily cancelled by an automatic procedure if not accessed for more than 40 days. In each user's home directory ($HOME) a file lists all deleted files for a given day.
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There is one $CINECA_SCRATCH area for each username on the machine.
$CINECA_SCRATCH does not have any disk quota. However, it is strongly recommended to maintain a low occupancy of this area in order to prevent the very dangerous filling condition. To verify if and how the cleaning procedure is active on a given cluster, check the Mott-of-the-Day.
$DRES: permanent, shared (among platforms and projects)
This is a repository area for collaborative work among different projects and across platforms. You need to explicitly ask for this kind of resource: it does not come as part of a project (mailto: superc@cineca.it).
File retention is related to life of DRES itself. Files in DRES will be conserved up to 6 months after DRES completion, then they will be cancelled. Several types of DRES are available, at present:
- FS: normal filesystem access on high throughput disks, shared among all HPC platforms (mounted only on login nodes);
- ARCH: magnetic tape archiving with a disk-like interface via LTFS;
- REPO: smart repository based on iRODS.
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$TAPE: permanent, user specific, shared
This is an archive area area conceived for saving personal data on magnetic media. The list of file is maintained on disks, the file content is moved automatically to tape using the LTFS technology. This archive space is not created by default for all users: you have to ask for it, by specifying the maximum space required (mailto: superc@cineca.it).
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A comprehensive discussion on how to manage your data can be found in a specific document.
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