Overview of available file systems

effective on July 13th, 2015

/scratch cleanup effective on Oct 1st, 2015

File system,

Environment Variable for Access

PurposeTypem overall net size and BandwidthBackup and snapshotsIntended lifetime, cleanup strategy Quota

/home

$HOME

Store source files, input data, small files

Globally accessible from login and compute nodes

GPFS, 100TB

backup to tape and snapshots

Account lifetime

100GB

per user

/work

$WORK 

Result files and data sets

Globally accessible from login and compute nodes

GPFS, 100TB

Backup upon request, at cost price.

Snapshots

3 years

50GB*

per group

/scratch

$SCRATCH 

Temporary huge result files

Accessible from the frontents and the compute nodes within one cluster.

Aries: GPFS 87TB

Bellatrix: GPFS 200TB

Castor: NFS 22TB

Deneb: GPFS 350TB

No backup, no snapshots

2 weeks

Automatic deletion of files older than 2 weeks may happen without notice

no

various

$TMPDIR

/tmp/${SLURM_JOB_ID}

Temporary, local file space for jobs on compute nodes.

Not available on login nodes.

 may varyNo backup, no snapshots

job execution

content is deleted after job end

no

 

* Space on work is charged for and, as such, the quota of the group depends on the amount of space purchased.  There is no backup by default but a laboratory may request such a service. The price for backup will be the cost price to SCITAS.

The price for work is 300 CHF per TB for 3 years.

Each group is allocated, for free, 50GB.

Security of user data

The contents of the home file-system are backed-up on a daily basis with a six month retention period. The backed up data are held at a separate physical location to the original data.

The contents of the work file-system are not backed up by default

The scratch file-systems are not backed-up under any circumstances.

The scratch file-systems are only for short-lived files and, in the case of insufficient free space, files older than two weeks may be deleted without notice in order to ensure the usability of the cluster.

Files belonging to a former user

When a user no longer has a valid account on the clusters any files belonging to him on home are removed from the servers. They will remain on tape for 6 months after the user has left EPFL. The head of the laboratory is responsible for ensuring that these data are correctly managed. He or she can ask for a retrieval from tape.

The work file-system is divided by laboratory and, as such, it is the responsibility of the head of the laboratory to ensure that the data are correctly managed.

Once a user is no longer accredited, files belonging to them in scratch can be deleted without notice.

How to recover snapshots

A snapshot is the state of a system at a particular point in time. On our clusters, the home and work filesystems are snapshotted daily and snapshots are kept for one week. This is particularly useful in case a user removes a file by mistake.

Daily snapshots of the home and work filesystems can be found in /home/.snapshots, /work/.snapshots, respectively.