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OLCF User Assistance Center

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User Home Directories (NFS)

See this article in context within the following user guides: Data | Eos | Rhea | Titan

Each user is provided a home directory to store frequently used items such as source code, binaries, and scripts.

User Home Path

Home directories are located in a Network File Service (NFS) that is accessible from all OLCF resources as /ccs/home/$USER.

The environment variable $HOME will always point to your current home directory. It is recommended, where possible, that you use this variable to reference your home directory. In cases in which using $HOME is not feasible, it is recommended that you use /ccs/home/$USER.

Users should note that since this is an NFS-mounted filesystem, its performance will not be as high as other filesystems.

User Home Quotas

Quotas are enforced on user home directories. To request an increased quota, contact the OLCF User Assistance Center. To view your current quota and usage, use the quota command:

$ quota -Qs
Disk quotas for user usrid (uid 12345):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
                  4858M   5000M   5000M           29379   4295m   4295m
User Home Backups

If you accidentally delete files from your home directory, you may be able to retrieve them. Online backups are performed at regular intervals. Hourly backups for the past 24 hours, daily backups for the last 7 days, and 1 weekly backup are available. It is possible that the deleted files are available in one of those backups. The backup directories are named hourly.*, daily.* , and weekly.* where * is the date/time stamp of the backup. For example, hourly.2016-12-01-0905 is an hourly backup made on December 1, 2016 at 9:05 AM.

The backups are accessed via the .snapshot subdirectory. Note that if you do an ls (even with the -a option) of any directory you won’t see a .snapshot subdirectory, but you’ll be able to do “ls .snapshot” nonetheless. This will show you the hourly/daily/weekly backups available. The .snapshot feature is available in any subdirectory of your home directory and will show the online backup of that subdirectory. In other words, you don’t have to start at /ccs/home/$USER and navigate the full directory structure; if you’re in a /ccs/home subdirectory several “levels” deep, an “ls .snapshot” will access the available backups of that subdirectory.

User Home Permissions

The default permissions for user home directories are 0750 (full access to the user, read and execute for the group). Users have the ability to change permissions on their home directories, although it is recommended that permissions be set to as restrictive as possible (without interfering with your work).

Special User Website Directory

User Home spaces may contain a directory named /www. If this directory exists, and if appropriate permissions exist, files in that directory will be accessible via the World Wide Web at http://users.nccs.gov/~user (where user is your userid).