Internal Storage
Users have three locations on Hamilton where they can store their files:
- Home directory (/home/<username>)
By default, new users are provided with 10GB of storage space in their home directory. Home directories are backed up and backups are kept for 30 days.
- Data directory (/nobackup/<username>)
New users are also provided with 600GB of storage space in their data directory. Please contact us if your research requires more disk space.
Unlike the home directories, data directories are not backed up. Please ensure you save a copy of anything you cannot easily recreate to another service, for example the PRS and SRS services provided by CIS.
Your current usage of your home and data directories can be seen by running the quota command on hamilton.
- Temporary directory ($TMPDIR)
In addition to the two areas above, each compute node has 400GB disk space available for temporary files. The disk space is accessible only from the node it is attached to. Space here can be reserved as part of a scheduled job and any files stored in $TMPDIR will be removed automatically at the end of that job.
Project directories for shared working
The directories above are intended for individual users Project PIs may also request a ‘project directory’, where access us shared by named project members. If you wish to request a project directory, please suggest a short name for the directory and provide a list of project members who should have access.
Project directories are set up as follows:
- Each directory is located in /projects and is accessible from all login and compute nodes.
- The default quota is 20GB, shared between the project members. To see how much space is free:
df -h /projects/<directory name>
- The directory is backed up. As with Hamilton home directories, backups are normally taken once a day and are kept for 30 days.
- The directory is for files that belong to the project, and ultimately to the University. This means:
- The space must not be used for personal files or for files that users expect to be private. We will assume that the directory contains no such files.
- Ownership of files may be transferred to the PI, for example at the PI’s request or if the original owner has left or changed role.
- If the PI leaves the University then ownership will revert to the head of the PI's department.
Using project directories
Access to a project directory is controlled by a unix group. The project PI will need to request that any new project members are added to this group. To check the current membership of a group, use:
getent group <unix group name>
Linux access permissions are specified for an item’s owner, group and others. The group access permissions for anything created in the project directory will refer to the project’s unix group. However, items moved from elsewhere on Hamilton may belong to a different group. For example, to check ownership and permissions for a file /projects/myproject/myfile, and update the group ownership to myproject_grp:
ls -l /projects/myproject/myfile
-rw-r--r-- 1 myusername other_grp 1234 Jan 1 12:00 myfile
chgrp myproject_grp myfile
ls -l /projects/myproject/myfile
-rw-r--r-- 1 myusername myproject_grp 1234 Jan 1 12:00 myfile
Project members can each create directories and files in /projects/<directory name>. Anything created there will have the owner’s normal access permissions, which by default means that other people with access to the parent directory can read files, but not write to them. The chmod command can be used to change permissions. For example, to allow members of the group to write to a file:
chmod g+w <file name>
Take care if granting write-access for directories, as it confers the rights to delete contents.