Since resources within the ARCC are shared, there are limitations in place to make sure there is fair and effective usage of the shared file systems. Usable file space is divided into user space and group space. There are limitations to each of these, both in terms of the total space available to users and groups, as well as to the total number of files available to users and groups.
Stokes
User Storage
User files on Stokes are located in /home/<username> and are stored on what is called the /lustre/fs0 file system. Each user has access to no more than 500 GB of space on /lustre/fs0 and no more than 400,000 separate files.
Group Storage
We have also provided space on the /lustre/fs0 file system for groups to use for shared storage. This is primarily intended to be used as space for users in a given research laboratory to build and install software used by many people in the group, when that software is proprietary or otherwise not a part of the general system software installed in /apps. This is to avoid users in the same lab installing the same software repeatedly. Group directories are in /groups/<groupname>. Note that quotas are shared so files owned by a user in /groups/<groupname> are charged to that user's quota.
Backup Policies
We do not back up user or group files. Users are expected to back up their own data and to keep their areas clean and well-maintained. The Stokes file systems are not intended for long-term storage.
Requesting More Resources
From time-to-time, specific project demands create a need for more space than is allocated. You may request access to more space or an increase in the file limitation temporarily based on project needs. To do so, please fill out and submit a Resource Expansion Request form. We will evaluate the request and may grant the request, depending on need and availability. Be sure to include the following information:
- Precisely what additional resources are needed (how many space or how many additional files -- do not say "as much as possible");
- Why these resources are needed above and beyond the standard resources;
- How long these resources will be required (do not say "indefinitely").