There are several distinct file spaces available on TRACE, each serving a different function.

• $HOME - /trace/home/<Andrew-id>
• $GROUP - /trace/group/<groupName>
• $PACKAGES - /trace/packages
• $LOCAL - /local

File permissions

Access to files in any TRACE-HPC space is governed by Unix file permissions. If  your data has additional security or compliance requirements, please contact trace-it-help@andrew.cmu.edu.

Unix file permissions

For detailed information on Unix file protections, see the man page for the chmod (change mode) command.
To share files with your group, give the group read and execute access for each directory from your top-level directory down to the directory that contains the files you want to share.
chmod g+rx directory-name
Then give the group read and execute access to each file you want to share.
chmod g+rx filename
To give the group the ability to edit or change a file, add write access to the group:
chmod g+rwx filename

Access Control Lists

If you want more fine-grained control than Unix file permissions allow —for example, if you want to give only certain members of a group access to  a file, but not all members—then you need to use Access Control Lists (ACLs). Suppose, for example, that you want to give janeuser read access to a file in a directory, but no one else in the group.
Use the setfacl (set file acl) command to give janeuser read and execute access on the directory:
setfacl -m user:janeuser:rx directory-name
for each directory from your top-level directory down to the directory that contains the file you want to share with janeuser. Then give janeuser access to a specific file with
setfacl -m user:janeuser:r filename
User janeuser will now be able to read this file, but no one else in the group will have access to it.
To see what ACLs are set on a file, use the getfacl (get file acl) command.
There are man pages for chmod, setfacl and getfacl.

$HOME

This is your TRACE home directory. It is the usual location for your batch scripts, source code and parameter files. Its path is /trace/home/username, where  username is your Andrew-id. You can refer to your home directory with the environment variable $HOME. Your home directory is visible to all of TRACE's nodes.
Your home directory is backed up daily.

Restoring from a snapshot

[ray@trace-login06 ~]$ cd /trace/home/.snapshot
[ray@trace-login06 .snapshot]$ ls
snap_2023-05-10_05_00_00_UTC snap_2023-05-13_05_00_00_UTC snap_2023-05-16_05_00_00_UTC
snap_2023-05-11_05_00_00_UTC snap_2023-05-14_05_00_00_UTC
snap_2023-05-12_05_00_00_UTC snap_2023-05-15_05_00_00_UTC

$HOME quota

Your home directory has a 25GB quota.
Account expiration
Three months after your account expires, the files in your home directory will be deleted.

GROUP

The path of your project directory is /trace/group/<groupname>

Group quota

250 GB Group wide quota(additional quota may be requested)

Grant expiration

Three months after a grant expires, the files in any group directories associated with that project will be deleted.

$LOCAL

Directory /local

Data removed at the end of the job.

Available on compute nodes.

PACKAGES

Directory /trace/packages

Central repository for software available to all users of the cluster

Hosted on the VAST array