User-Centric Data Storage¶
The following table summarizes user-centric storage areas available on OLCF resources and lists relevant polices.
User-Centric Storage Areas
|Area||Path||Type||Permissions||Quota||Backups||Purged||Retention||On Compute Nodes|
||NFS||User set||50 GB||Yes||No||90 days||Read-only|
|User Archive ||
||HPSS||User set||2TB||No||No||90 days||No|
|User Archive ||
|||This entry is for legacy User Archive directories which contained user data on January 14, 2020. There is also a quota/limit of 2,000 files on this directory.|
|||User Archive directories that were created (or had no user data) after January 14, 2020. Settings other than permissions are not applicable because directories are root-owned and contain no user files.|
User Home Directories (NFS)¶
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
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,
$ quota -Qs Disk quotas for user usrid (uid 12345): Filesystem blocks quota limit grace files quota limit grace nccsfiler1a.ccs.ornl.gov:/vol/home 4858M 5000M 5000M 29379 4295m 4295m
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
User Home Backups¶
If you accidentally delete files from your home directory
/ccs/home/$USER), 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 once-weekly backups are available. It is
possible that the deleted files are available in one of those backups. The
backup directories are named
* is the date/time stamp of backup creation. For example,
hourly.2020-01-01-0905 is an hourly backup made on January 1st, 2020 at
The backups are accessed via the
.snapshot subdirectory. Note that
alone (or even
ls -a) will not show the
.snapshot subdirectory exists,
ls .snapshot will show its contents. The
.snapshot feature is
available in any subdirectory of your home directory and will show the online
backups available for that subdirectory.
To retrieve a backup, simply copy it into your desired destination with the
User Website Directory¶
Users interested in sharing files publicly via the World Wide Web can request a
user website directory be created for their account. User website directories
~/www) have a 5GB storage quota and allow access to files at
user is your userid). If you are
interested in having a user website directory created, please contact the User
Assistance Center at email@example.com.
User Archive Directories (HPSS)¶
Use of User Archive areas for data storage is deprecated as of January 14, 2020. The user archive area for any user account created after that date (or for any user archive directory that is empty of user files after that date) will contain only symlinks to the top-level directories for each of the user’s projects on HPSS. Users with existing data in a User Archive directory are encouraged to move that data to an appropriate project-based directory as soon as possible.
The information below is simply for reference for those users with existing data in User Archive directories.
The High Performance Storage System (HPSS) at the OLCF provides longer-term storage for the large amounts of data created on the OLCF compute systems. The mass storage facility consists of tape and disk storage components, servers, and the HPSS software. After data is uploaded, it persists on disk for some period of time. The length of its life on disk is determined by how full the disk caches become. When data is migrated to tape, it is done so in a first-in, first-out fashion.
User archive areas on HPSS are intended for storage of data not immediately needed in either User Home directories (NFS) or User Work directories (GPFS). User Archive directories should not be used to store project-related data. Rather, Project Archive directories should be used for project data.
User archive directories are located at
User Archive Access¶
Each OLCF user receives an HPSS account automatically. Users can transfer data to HPSS from any OLCF system using the HSI or HTAR utilities. For more information on using HSI or HTAR, see the HPSS Data Archival System .