File Storage Information

Home Area

Each user has, by default, 60GB of space in their home area that is stored on a fast, NFS server with redundancy against Hard Disk failure. Backups (excluding *.root files) are taken every couple of days. This storage is generally meant for code and documents as it's designed for fast access to small files, e.g. compilation of code. If you find you need more space then email MWS. Also, by default all files created in your home area can only be accessed by you. Use the chmod command to allow read access for others if you wish.

Mass Storage

In addition to your home area, there is a general mass storage system running the Moose Filesystem which can be accessed from:

/disk/moose

This contains 855TB of storage but only half of that is usable due two copies of each file being stored for redundancy. There is no other backup procedure so though it's very unlikely, if we have two disks fail on different servers in quick succession (i.e. before the system has chance to rebalance) there will be data loss. If you want to store files with even less chance of loss, put them in:

/disk/moose/critical

as 4 copies of these files are kept. Don't abuse this though as MWS will ask this to be cleaned first if space is running low!

Under both of these directories are folders for each experiment. Only experiment members have read/write access to these but they can be organised as the experiment wishes.

Scratch Area

On each linux machine there is a /scratch area which writes to the physical disk of the machine. This can be useful for storing large files that won't fit into /tmp. Note however, that files here should be considered volatile and copied elsewhere for long term storage. Full or damaged disks and reinstallation of the machine could all result in data loss.