HPC/Sharing Files

Introduction

When you collaborate with other users on a common project on Carbon, you may wish to share files among you. There are several ways to achieve this, largely distinguished by how often and for how long sharing is needed.

Sharing Types

Using a Unix group

• suitable for ongoing exchanges
• a matching group directory will be located in /home/share/groupname/
• mutually writable among members, without concessions to other users
• permissions are inherited for all files placed there

Typically, a group name and directory is created automatically for each CNM proposal that has more than one user. You can access the shared directories for proposals by one of the following:

/home/share/cnm12345
~cnm12345

The system admin can create a the group and directory for you. To request the creation of an ad-hoc Unix group, please send the following information:

1. a group name which should be short (up to some 8 chars) and distinctive
2. the user list (later changes are easy)

Sharing in your own directories

You can give access to some your directories in your respective $HOME or $SANDBOX by opening permissions.

• typically one-way (unless you grant world-write)
• likely to need chmod whenever more files are placed.

You can arrange this on your own as follows:

Owner

chmod a+x $HOME/
mkdir $HOME/share
# populate ..
chmod -R a+rX $HOME/share

Reader

cd /home/owner/share
ls
cp -p ....

If you have particularly largefiles, replace $HOME and /home by $SANDBOX and /sandbox, respectively.

Using a /tmp directory

• suitable for one-off exchanges
• typically fairly loose permissions
• resides on only one host
• world-write not recommended
• likely to need chmod whenever more files are placed

You can arrange this on your own as well:

mkdir /tmp/foo
# populate ..
chmod -R a+rX /tmp/foo