Filesystem overview

PSMN provides access to several file systems, each with distinct storage characteristics. Each user and group get access to a set of pre-defined directories in these file systems to store their data.

Important

PSMN is a computing center, not a storage center.

Storage resources are limited and are shared among many users. They are meant to store data and code associated with projects for which you are using PSMN’s computational resources. This space is for work actively being computed on, and SHOULD NOT BE USED AS A TARGET FOR BACKUPS FROM OTHER SYSTEMS.

If you’re looking for a long-term storage solution for research data, CC-IN2P3 offers the iRods storage filesystem, which is specifically intended for this usage. Contact PSMN’s Staff for access.

Those file systems are shared with other users, and are subject to quota limits and for some of them, purge policies (time-residency limits) :

Danger

There is no backup of the data stored on PSMN storages. Any removed file is lost forever. It is the users’s responsibility to keep a copy of the contents of their storage in a safe place.

• Accessing filesystems
• Quotas and limits
• Where to store files?
• Keep your home directory clean
• Use scratch
• Transfer protocols

Features and purpose

Name	Type	snapshots	quotas	Performance	Purpose
$HOME	NFS	yes	yes	low, medium	small, important files, source code, executables, configuration files
/Xnfs	NFS	yes	yes	low, medium	teams & groups files (same as $HOME)
$SCRATCH	glusterfs	no	no	high	large temporary files, checkpoints, raw temporary input/output
local scratch (ssd, disk)	ext4, zfs	no	no	medium, high	job specific output requiring IOPS [1] (120 days lifetime residency)

Important

/tmp special case.

All our nodes use SIDUS OS distribution system. In that system, /tmp is located in RAM. Do NOT use it to store files. (same apply for /var/tmp or /dev/shm).

[1]

See IOPS